CVE-2026-31669

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31669", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.130Z", "datePublished": "2026-04-24T14:45:17.295Z", "dateUpdated": "2026-11-10T12:45:20.321Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:24:19.282Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix slab-use-after-free in __inet_lookup_established\n\nThe ehash table lookups are lockless and rely on\nSLAB_TYPESAFE_BY_RCU to guarantee socket memory stability\nduring RCU read-side critical sections. Both tcp_prot and\ntcpv6_prot have their slab caches created with this flag\nvia proto_register().\n\nHowever, MPTCP's mptcp_subflow_init() copies tcpv6_prot into\ntcpv6_prot_override during inet_init() (fs_initcall, level 5),\nbefore inet6_init() (module_init/device_initcall, level 6) has\ncalled proto_register(&tcpv6_prot). At that point,\ntcpv6_prot.slab is still NULL, so tcpv6_prot_override.slab\nremains NULL permanently.\n\nThis causes MPTCP v6 subflow child sockets to be allocated via\nkmalloc (falling into kmalloc-4k) instead of the TCPv6 slab\ncache. The kmalloc-4k cache lacks SLAB_TYPESAFE_BY_RCU, so\nwhen these sockets are freed without SOCK_RCU_FREE (which is\ncleared for child sockets by design), the memory can be\nimmediately reused. Concurrent ehash lookups under\nrcu_read_lock can then access freed memory, triggering a\nslab-use-after-free in __inet_lookup_established.\n\nFix this by splitting the IPv6-specific initialization out of\nmptcp_subflow_init() into a new mptcp_subflow_v6_init(), called\nfrom mptcp_proto_v6_init() before protocol registration. This\nensures tcpv6_prot_override.slab correctly inherits the\nSLAB_TYPESAFE_BY_RCU slab cache."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - Remote IPv6 TCP/MPTCP packets reach `tcp_v6_rcv()` and its lockless established-socket ehash lookup through the normal network receive path. A reachable IPv6 MPTCP service can be exercised over the network without local execution.\nAC:L - The vulnerability is a race between freeing an MPTCP IPv6 child socket and concurrent ehash lookup, but the attacker can drive both sides by repeatedly creating/closing MPTCP connections or subflows while sending packets. Under the required rule, this attacker-controlled race is Low complexity.\nPR:N - No local account, capability, namespace setup, or protocol authentication is needed to send the packets that reach the vulnerable receive path. The only environmental requirement is a reachable MPTCP IPv6 listener.\nUI:N - No victim user action is required after the vulnerable service is listening. Network traffic alone can trigger allocation, teardown, and lookup of the affected sockets.\nS:U - The flaw is in the kernel networking stack and impacts kernel-managed resources within the same security authority. It is not a VM escape, IOMMU bypass, or cross-scope boundary violation.\nC:H - This is a kernel heap use-after-free where freed socket memory can be immediately reused while lockless lookup still dereferences it. Such UAF conditions are defensibly capable of exposing kernel memory or primitives useful for broader disclosure.\nI:H - The stale socket pointer can reference attacker-influenced reused kmalloc memory during refcounting and socket processing. Kernel heap UAF is treated as high integrity impact because it can plausibly be developed into write/control-flow corruption.\nA:H - The reported condition is a slab-use-after-free in `__inet_lookup_established`, which can crash or oops the kernel. A remote attacker can trigger it repeatedly against a reachable affected service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mptcp/protocol.c", "net/mptcp/protocol.h", "net/mptcp/subflow.c"], "versions": [{"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47", "status": "affected", "versionType": "git"}, {"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "fb1f54b7d16f393b8b65d328410f78b4beea8fcc", "status": "affected", "versionType": "git"}, {"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "3fd6547f5b8ac99687be6d937a0321efda760597", "status": "affected", "versionType": "git"}, {"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "eb9c6aeb512f877cf397deb1e4526f646c70e4a7", "status": "affected", "versionType": "git"}, {"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "15fa9ead4d5e6b6b9c794e84144146c917f2cb62", "status": "affected", "versionType": "git"}, {"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "b313e9037d98c13938740e5ebda7852929366dff", "status": "affected", "versionType": "git"}, {"version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "9b55b253907e7431210483519c5ad711a37dafa1", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mptcp/protocol.c", "net/mptcp/protocol.h", "net/mptcp/subflow.c"], "versions": [{"version": "5.12", "status": "affected"}, {"version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.169", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.135", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.82", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.23", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.13", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.15.203"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.1.169"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.6.135"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.12.82"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.18.23"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.19.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47"}, {"url": "https://git.kernel.org/stable/c/fb1f54b7d16f393b8b65d328410f78b4beea8fcc"}, {"url": "https://git.kernel.org/stable/c/3fd6547f5b8ac99687be6d937a0321efda760597"}, {"url": "https://git.kernel.org/stable/c/eb9c6aeb512f877cf397deb1e4526f646c70e4a7"}, {"url": "https://git.kernel.org/stable/c/15fa9ead4d5e6b6b9c794e84144146c917f2cb62"}, {"url": "https://git.kernel.org/stable/c/b313e9037d98c13938740e5ebda7852929366dff"}, {"url": "https://git.kernel.org/stable/c/9b55b253907e7431210483519c5ad711a37dafa1"}], "title": "mptcp: fix slab-use-after-free in __inet_lookup_established", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"x_adpType": "supplier", "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-11-10T12:45:20.321Z"}, "affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}]}, {"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-31669", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:12:01.538596Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T18:56:03.360Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "versions": [{"status": "affected", "version": "V3.1.7", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "x_adpType": "supplier", "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}], "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-11-10T12:45:20.321Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-31669", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:12:01.538596Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:12:02.982Z"}}], "cna": {"title": "mptcp: fix slab-use-after-free in __inet_lookup_established", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 9.8, "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - Remote IPv6 TCP/MPTCP packets reach `tcp_v6_rcv()` and its lockless established-socket ehash lookup through the normal network receive path. A reachable IPv6 MPTCP service can be exercised over the network without local execution.\nAC:L - The vulnerability is a race between freeing an MPTCP IPv6 child socket and concurrent ehash lookup, but the attacker can drive both sides by repeatedly creating/closing MPTCP connections or subflows while sending packets. Under the required rule, this attacker-controlled race is Low complexity.\nPR:N - No local account, capability, namespace setup, or protocol authentication is needed to send the packets that reach the vulnerable receive path. The only environmental requirement is a reachable MPTCP IPv6 listener.\nUI:N - No victim user action is required after the vulnerable service is listening. Network traffic alone can trigger allocation, teardown, and lookup of the affected sockets.\nS:U - The flaw is in the kernel networking stack and impacts kernel-managed resources within the same security authority. It is not a VM escape, IOMMU bypass, or cross-scope boundary violation.\nC:H - This is a kernel heap use-after-free where freed socket memory can be immediately reused while lockless lookup still dereferences it. Such UAF conditions are defensibly capable of exposing kernel memory or primitives useful for broader disclosure.\nI:H - The stale socket pointer can reference attacker-influenced reused kmalloc memory during refcounting and socket processing. Kernel heap UAF is treated as high integrity impact because it can plausibly be developed into write/control-flow corruption.\nA:H - The reported condition is a slab-use-after-free in `__inet_lookup_established`, which can crash or oops the kernel. A remote attacker can trigger it repeatedly against a reachable affected service."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47", "versionType": "git"}, {"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "fb1f54b7d16f393b8b65d328410f78b4beea8fcc", "versionType": "git"}, {"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "3fd6547f5b8ac99687be6d937a0321efda760597", "versionType": "git"}, {"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "eb9c6aeb512f877cf397deb1e4526f646c70e4a7", "versionType": "git"}, {"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "15fa9ead4d5e6b6b9c794e84144146c917f2cb62", "versionType": "git"}, {"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "b313e9037d98c13938740e5ebda7852929366dff", "versionType": "git"}, {"status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "lessThan": "9b55b253907e7431210483519c5ad711a37dafa1", "versionType": "git"}], "programFiles": ["net/mptcp/protocol.c", "net/mptcp/protocol.h", "net/mptcp/subflow.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"status": "unaffected", "version": "0", "lessThan": "5.12", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.203", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.169", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.135", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.82", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.23", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.13", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/mptcp/protocol.c", "net/mptcp/protocol.h", "net/mptcp/subflow.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47"}, {"url": "https://git.kernel.org/stable/c/fb1f54b7d16f393b8b65d328410f78b4beea8fcc"}, {"url": "https://git.kernel.org/stable/c/3fd6547f5b8ac99687be6d937a0321efda760597"}, {"url": "https://git.kernel.org/stable/c/eb9c6aeb512f877cf397deb1e4526f646c70e4a7"}, {"url": "https://git.kernel.org/stable/c/15fa9ead4d5e6b6b9c794e84144146c917f2cb62"}, {"url": "https://git.kernel.org/stable/c/b313e9037d98c13938740e5ebda7852929366dff"}, {"url": "https://git.kernel.org/stable/c/9b55b253907e7431210483519c5ad711a37dafa1"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix slab-use-after-free in __inet_lookup_established\n\nThe ehash table lookups are lockless and rely on\nSLAB_TYPESAFE_BY_RCU to guarantee socket memory stability\nduring RCU read-side critical sections. Both tcp_prot and\ntcpv6_prot have their slab caches created with this flag\nvia proto_register().\n\nHowever, MPTCP's mptcp_subflow_init() copies tcpv6_prot into\ntcpv6_prot_override during inet_init() (fs_initcall, level 5),\nbefore inet6_init() (module_init/device_initcall, level 6) has\ncalled proto_register(&tcpv6_prot). At that point,\ntcpv6_prot.slab is still NULL, so tcpv6_prot_override.slab\nremains NULL permanently.\n\nThis causes MPTCP v6 subflow child sockets to be allocated via\nkmalloc (falling into kmalloc-4k) instead of the TCPv6 slab\ncache. The kmalloc-4k cache lacks SLAB_TYPESAFE_BY_RCU, so\nwhen these sockets are freed without SOCK_RCU_FREE (which is\ncleared for child sockets by design), the memory can be\nimmediately reused. Concurrent ehash lookups under\nrcu_read_lock can then access freed memory, triggering a\nslab-use-after-free in __inet_lookup_established.\n\nFix this by splitting the IPv6-specific initialization out of\nmptcp_subflow_init() into a new mptcp_subflow_v6_init(), called\nfrom mptcp_proto_v6_init() before protocol registration. This\nensures tcpv6_prot_override.slab correctly inherits the\nSLAB_TYPESAFE_BY_RCU slab cache."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.203", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.169", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.135", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.82", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.23", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.19.13", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0", "versionStartIncluding": "5.12"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:24:19.282Z"}}}, "cveMetadata": {"cveId": "CVE-2026-31669", "state": "PUBLISHED", "dateUpdated": "2026-11-10T12:45:20.321Z", "dateReserved": "2026-03-09T15:48:24.130Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-04-24T14:45:17.295Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/mptcp/protocol.c", "net/mptcp/protocol.h", "net/mptcp/subflow.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}, {"lessThan": "fb1f54b7d16f393b8b65d328410f78b4beea8fcc", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}, {"lessThan": "3fd6547f5b8ac99687be6d937a0321efda760597", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}, {"lessThan": "eb9c6aeb512f877cf397deb1e4526f646c70e4a7", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}, {"lessThan": "15fa9ead4d5e6b6b9c794e84144146c917f2cb62", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}, {"lessThan": "b313e9037d98c13938740e5ebda7852929366dff", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}, {"lessThan": "9b55b253907e7431210483519c5ad711a37dafa1", "status": "affected", "version": "b19bc2945b40b9fd38e835700907ffe8534ef0de", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/mptcp/protocol.c", "net/mptcp/protocol.h", "net/mptcp/subflow.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"lessThan": "5.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.203", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.169", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.135", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.82", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.23", "versionType": "semver"}, {"lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.13", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"affectedData": [{"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom"}]}, {"defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom"}]}], "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "AA3D6441-4F2E-41AB-A26D-388B03A5932F", "versionEndExcluding": "5.15.203", "versionStartIncluding": "5.12.1", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "DBEC0E5D-641C-4E98-A6D9-5799B10CE451", "versionEndExcluding": "6.1.169", "versionStartIncluding": "5.16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "15C1A1B2-14EE-494C-AF3E-D5A7BA640B39", "versionEndExcluding": "6.6.135", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "02904CAE-71D2-45B3-9EC3-F6A9D18B6307", "versionEndExcluding": "6.12.82", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "E9E09FDD-9EE3-4A56-92E2-2B30AFD0072F", "versionEndExcluding": "6.18.23", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "1490EF9B-9080-481C-8D22-1306AAE664E4", "versionEndExcluding": "6.19.13", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.12:-:*:*:*:*:*:*", "matchCriteriaId": "75EB504D-4A83-4C67-9C8D-FD9C6C8EB4CD", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix slab-use-after-free in __inet_lookup_established\n\nThe ehash table lookups are lockless and rely on\nSLAB_TYPESAFE_BY_RCU to guarantee socket memory stability\nduring RCU read-side critical sections. Both tcp_prot and\ntcpv6_prot have their slab caches created with this flag\nvia proto_register().\n\nHowever, MPTCP's mptcp_subflow_init() copies tcpv6_prot into\ntcpv6_prot_override during inet_init() (fs_initcall, level 5),\nbefore inet6_init() (module_init/device_initcall, level 6) has\ncalled proto_register(&tcpv6_prot). At that point,\ntcpv6_prot.slab is still NULL, so tcpv6_prot_override.slab\nremains NULL permanently.\n\nThis causes MPTCP v6 subflow child sockets to be allocated via\nkmalloc (falling into kmalloc-4k) instead of the TCPv6 slab\ncache. The kmalloc-4k cache lacks SLAB_TYPESAFE_BY_RCU, so\nwhen these sockets are freed without SOCK_RCU_FREE (which is\ncleared for child sockets by design), the memory can be\nimmediately reused. Concurrent ehash lookups under\nrcu_read_lock can then access freed memory, triggering a\nslab-use-after-free in __inet_lookup_established.\n\nFix this by splitting the IPv6-specific initialization out of\nmptcp_subflow_init() into a new mptcp_subflow_v6_init(), called\nfrom mptcp_proto_v6_init() before protocol registration. This\nensures tcpv6_prot_override.slab correctly inherits the\nSLAB_TYPESAFE_BY_RCU slab cache."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmptcp: corrige el uso despu\u00e9s de liberaci\u00f3n de slab en __inet_lookup_established\n\nLas b\u00fasquedas en la tabla ehash no tienen bloqueo y dependen de SLAB_TYPESAFE_BY_RCU para garantizar la estabilidad de la memoria del socket durante las secciones cr\u00edticas del lado de lectura de RCU. Tanto tcp_prot como tcpv6_prot tienen sus cach\u00e9s de slab creadas con esta bandera a trav\u00e9s de proto_register().\n\nSin embargo, mptcp_subflow_init() de MPTCP copia tcpv6_prot en tcpv6_prot_override durante inet_init() (fs_initcall, nivel 5), antes de que inet6_init() (module_init/device_initcall, nivel 6) haya llamado a proto_register(ref:tcpv6_prot). En ese punto, tcpv6_prot.slab sigue siendo NULL, por lo que tcpv6_prot_override.slab permanece NULL permanentemente.\n\nEsto hace que los sockets hijos de subflujo MPTCP v6 se asignen a trav\u00e9s de kmalloc (cayendo en kmalloc-4k) en lugar de la cach\u00e9 de slab de TCPv6. La cach\u00e9 kmalloc-4k carece de SLAB_TYPESAFE_BY_RCU, por lo que cuando estos sockets se liberan sin SOCK_RCU_FREE (que se borra para los sockets hijos por dise\u00f1o), la memoria puede ser reutilizada inmediatamente. Las b\u00fasquedas concurrentes de ehash bajo rcu_read_lock pueden entonces acceder a memoria liberada, desencadenando un uso despu\u00e9s de liberaci\u00f3n de slab en __inet_lookup_established.\n\nEsto se corrige dividiendo la inicializaci\u00f3n espec\u00edfica de IPv6 de mptcp_subflow_init() en una nueva mptcp_subflow_v6_init(), llamada desde mptcp_proto_v6_init() antes del registro del protocolo. Esto asegura que tcpv6_prot_override.slab herede correctamente la cach\u00e9 de slab SLAB_TYPESAFE_BY_RCU."}], "id": "CVE-2026-31669", "lastModified": "2026-11-11T23:10:00.263", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-31669", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:12:01.538596Z", "version": "2.0.3"}}]}, "published": "2026-04-24T15:16:46.663", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/15fa9ead4d5e6b6b9c794e84144146c917f2cb62"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/3fd6547f5b8ac99687be6d937a0321efda760597"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9b55b253907e7431210483519c5ad711a37dafa1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b313e9037d98c13938740e5ebda7852929366dff"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/eb9c6aeb512f877cf397deb1e4526f646c70e4a7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/fb1f54b7d16f393b8b65d328410f78b4beea8fcc"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-416"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: mptcp: fix slab-use-after-free in __inet_lookup_established", "id": "2461503", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2461503"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-763", "details": ["A flaw was found in the Linux kernel's Multipath TCP (MPTCP) implementation. Due to incorrect memory allocation for IPv6 subflow child sockets, a use-after-free vulnerability exists. A remote attacker could exploit this by triggering concurrent lookups in the kernel's hash table, potentially leading to a denial of service or arbitrary code execution."], "name": "CVE-2026-31669", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-31669\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31669\nhttps://lore.kernel.org/linux-cve-announce/2026042406-CVE-2026-31669-0e0d@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,f6e1f25fa5e733570f6d6fe37a4dfed2a0deba47)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,fb1f54b7d16f393b8b65d328410f78b4beea8fcc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,3fd6547f5b8ac99687be6d937a0321efda760597)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,eb9c6aeb512f877cf397deb1e4526f646c70e4a7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,15fa9ead4d5e6b6b9c794e84144146c917f2cb62)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,b313e9037d98c13938740e5ebda7852929366dff)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b19bc2945b40b9fd38e835700907ffe8534ef0de,9b55b253907e7431210483519c5ad711a37dafa1)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "5.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[5.15.203,5.15.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.1.169,6.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.6.135,6.6.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.82,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.23,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.19.13,6.19.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "analysis": {"en": {"generated_at": "2026-04-28T13:42:23.774205+00:00", "value": {"mitigation_remediation": ["Apply the latest kernel update that contains the MPTCP slab use\u2011after\u2011free fix", "Reboot the affected machines so that the updated kernel image is actively used", "If the system cannot be patched immediately, consider disabling MPTCP or restricting its use"], "summary": {"action": "Immediate Patch", "impact": "Use\u2011After\u2011Free in the Linux kernel that can lead to memory corruption and potentially arbitrary code execution"}, "threat_synthesis": {"affected_systems": "The flaw exists in Linux kernel releases 5.12 and all 7.0 release candidates up to rc7. Systems that run these kernels with MPTCP enabled and that establish IPv6 subflows are vulnerable. The fix was applied before the stable 7.0 rc7 release, so kernels derived from that branch after the corresponding commit include the remediation.", "description_and_impact": "A fault in Multicast TCP (MPTCP) initialization causes the TCPv6 slab cache pointer to remain null. When IPv6 subflow child sockets are allocated via kmalloc instead of the intended TCPv6 slab cache, the memory is not protected by SLAB_TYPESAFE_BY_RCU. If such sockets are freed while an RCU read\u2011side critical section is in progress, concurrent __inet_lookup_established hash table lookups can access freed memory, resulting in a slab\u2011use\u2011after\u2011free. This memory corruption (CWE\u2011416) can allow an attacker to trigger arbitrary kernel code execution or a denial\u2011of\u2011service condition if the fault occurs in a privileged context.", "risk_and_exploitability": "With a CVSS score of 9.8 it is classified as Critical; the EPSS score of less than 1% indicates a low probability of active exploitation at present. The vulnerability is not listed in the CISA KEV catalog. Attackers would likely need to trigger concurrent IPv6 subflow operations while a user space process holds an RCU read lock, a scenario that could be achieved by a local or privileged user that can open sockets. The risk is primarily local, but any compromised process could affect the host or connected network services."}}}}, "created": "2026-04-27T19:30:11.872944+00:00", "updated": "2026-04-28T13:45:06.144542+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}