CVE-2026-31406

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31406", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.086Z", "datePublished": "2026-04-06T07:38:18.840Z", "dateUpdated": "2026-08-05T12:22:15.395Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:22:15.395Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()\n\nAfter cancel_delayed_work_sync() is called from\nxfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining\nstates via __xfrm_state_delete(), which calls\nxfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work.\n\nThe following is a simple race scenario:\n\n cpu0 cpu1\n\ncleanup_net() [Round 1]\n ops_undo_list()\n xfrm_net_exit()\n xfrm_nat_keepalive_net_fini()\n cancel_delayed_work_sync(nat_keepalive_work);\n xfrm_state_fini()\n xfrm_state_flush()\n xfrm_state_delete(x)\n __xfrm_state_delete(x)\n xfrm_nat_keepalive_state_updated(x)\n schedule_delayed_work(nat_keepalive_work);\n rcu_barrier();\n net_complete_free();\n net_passive_dec(net);\n llist_add(&net->defer_free_list, &defer_free_list);\n\ncleanup_net() [Round 2]\n rcu_barrier();\n net_complete_free()\n kmem_cache_free(net_cachep, net);\n nat_keepalive_work()\n // on freed net\n\nTo prevent this, cancel_delayed_work_sync() is replaced with\ndisable_delayed_work_sync()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The vulnerable path is reached through local namespace lifecycle and NETLINK_XFRM state configuration, not by remote packet processing. An attacker can create an affected outbound ESP-in-UDP XFRM state locally and tear down the network namespace.\nAC:L - The attacker controls creation of the NAT keepalive state and repeated teardown of the network namespace; the work reschedule after cancel is a direct consequence of the cleanup ordering. Any scheduling race can be retried and influenced locally, so there are no hard external conditions.\nPR:L - XFRM netlink operations require CAP_NET_ADMIN in the target network namespace. This is reachable by an unprivileged local user through a user namespace plus network namespace where they hold CAP_NET_ADMIN.\nUI:N - No victim action is required after the attacker runs local code. The attacker can configure the state and trigger namespace cleanup directly.\nS:U - The vulnerability corrupts kernel memory within the same kernel security authority. It is a standard local kernel compromise scenario, not a VM or hardware boundary escape.\nC:H - This is a use-after-free of a network namespace embedded delayed_work object and subsequent XFRM/netns state access. Per kernel scoring guidance, UAFs are treated as enabling high confidentiality impact.\nI:H - The dangling work item can operate on freed and potentially reclaimed kernel memory, giving a plausible path to memory corruption and control-flow compromise. Per kernel scoring guidance, UAFs are treated as high integrity impact.\nA:H - At minimum, executing delayed work on a freed struct net can dereference freed XFRM state and namespace data, causing an oops or panic. Repeated local triggering can reliably deny service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_nat_keepalive.c"], "versions": [{"version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "lessThan": "32d0f44c2f14d60fe8e920e69a28c11051543ec1", "status": "affected", "versionType": "git"}, {"version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "lessThan": "2255ed6adbc3100d2c4a83abd9d0396d04b87792", "status": "affected", "versionType": "git"}, {"version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "lessThan": "21f2fc49ca6faa393c31da33b8a4e6c41fc84c13", "status": "affected", "versionType": "git"}, {"version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "lessThan": "daf8e3b253aa760ff9e96c7768a464bc1d6b3c90", "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/xfrm/xfrm_nat_keepalive.c"], "versions": [{"version": "6.11", "status": "affected"}, {"version": "0", "lessThan": "6.11", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.80", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.11", "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": "6.11", "versionEndExcluding": "6.12.80"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.18.21"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.19.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/32d0f44c2f14d60fe8e920e69a28c11051543ec1"}, {"url": "https://git.kernel.org/stable/c/2255ed6adbc3100d2c4a83abd9d0396d04b87792"}, {"url": "https://git.kernel.org/stable/c/21f2fc49ca6faa393c31da33b8a4e6c41fc84c13"}, {"url": "https://git.kernel.org/stable/c/daf8e3b253aa760ff9e96c7768a464bc1d6b3c90"}], "title": "xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/xfrm/xfrm_nat_keepalive.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "32d0f44c2f14d60fe8e920e69a28c11051543ec1", "status": "affected", "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "versionType": "git"}, {"lessThan": "2255ed6adbc3100d2c4a83abd9d0396d04b87792", "status": "affected", "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "versionType": "git"}, {"lessThan": "21f2fc49ca6faa393c31da33b8a4e6c41fc84c13", "status": "affected", "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "versionType": "git"}, {"lessThan": "daf8e3b253aa760ff9e96c7768a464bc1d6b3c90", "status": "affected", "version": "f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/xfrm/xfrm_nat_keepalive.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.11"}, {"lessThan": "6.11", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.80", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.21", "versionType": "semver"}, {"lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "3C886EDB-88C5-47BE-9133-37C769192535", "versionEndExcluding": "6.12.80", "versionStartIncluding": "6.11", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE", "versionEndExcluding": "6.18.21", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7", "versionEndExcluding": "6.19.11", "versionStartIncluding": "6.19", "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}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()\n\nAfter cancel_delayed_work_sync() is called from\nxfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining\nstates via __xfrm_state_delete(), which calls\nxfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work.\n\nThe following is a simple race scenario:\n\n cpu0 cpu1\n\ncleanup_net() [Round 1]\n ops_undo_list()\n xfrm_net_exit()\n xfrm_nat_keepalive_net_fini()\n cancel_delayed_work_sync(nat_keepalive_work);\n xfrm_state_fini()\n xfrm_state_flush()\n xfrm_state_delete(x)\n __xfrm_state_delete(x)\n xfrm_nat_keepalive_state_updated(x)\n schedule_delayed_work(nat_keepalive_work);\n rcu_barrier();\n net_complete_free();\n net_passive_dec(net);\n llist_add(&net->defer_free_list, &defer_free_list);\n\ncleanup_net() [Round 2]\n rcu_barrier();\n net_complete_free()\n kmem_cache_free(net_cachep, net);\n nat_keepalive_work()\n // on freed net\n\nTo prevent this, cancel_delayed_work_sync() is replaced with\ndisable_delayed_work_sync()."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nxfrm: Corrige la reprogramaci\u00f3n del trabajo despu\u00e9s de la cancelaci\u00f3n en xfrm_nat_keepalive_net_fini()\n\nDespu\u00e9s de que se llama a cancel_delayed_work_sync() desde xfrm_nat_keepalive_net_fini(), xfrm_state_fini() vac\u00eda los estados restantes a trav\u00e9s de __xfrm_state_delete(), que llama a xfrm_nat_keepalive_state_updated() para reprogramar nat_keepalive_work.\n\nEl siguiente es un escenario de carrera simple:\n\n cpu0 cpu1\n\ncleanup_net() [Ronda 1]\n ops_undo_list()\n xfrm_net_exit()\n xfrm_nat_keepalive_net_fini()\n cancel_delayed_work_sync(nat_keepalive_work);\n xfrm_state_fini()\n xfrm_state_flush()\n xfrm_state_delete(x)\n __xfrm_state_delete(x)\n xfrm_nat_keepalive_state_updated(x)\n schedule_delayed_work(nat_keepalive_work);\n rcu_barrier();\n net_complete_free();\n net_passive_dec(net);\n llist_add(&net -> defer_free_list, &defer_free_list);\n\ncleanup_net() [Ronda 2]\n rcu_barrier();\n net_complete_free()\n kmem_cache_free(net_cachep, net);\n nat_keepalive_work()\n // en net liberado\n\nPara evitar esto, cancel_delayed_work_sync() se reemplaza con disable_delayed_work_sync()."}], "id": "CVE-2026-31406", "lastModified": "2026-07-24T22:10:00.140", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-04-06T08:16:38.457", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/21f2fc49ca6faa393c31da33b8a4e6c41fc84c13"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2255ed6adbc3100d2c4a83abd9d0396d04b87792"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/32d0f44c2f14d60fe8e920e69a28c11051543ec1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/daf8e3b253aa760ff9e96c7768a464bc1d6b3c90"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()", "id": "2455332", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2455332"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in the Linux kernel, specifically within its xfrm (IP eXtensible FRamework) component. This vulnerability arises from a race condition during network cleanup, where a scheduled task (nat_keepalive_work) can be re-activated and attempt to operate on memory that has already been freed. This 'use-after-free' condition could allow a local attacker to cause the system to crash, leading to a denial of service, or potentially execute unauthorized code."], "name": "CVE-2026-31406", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-06T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-31406\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31406\nhttps://lore.kernel.org/linux-cve-announce/2026040628-CVE-2026-31406-e2f3@gregkh/T"], "statement": "After `cancel_delayed_work_sync()` in `xfrm_nat_keepalive_net_fini()`, state deletion could reschedule `nat_keepalive_work` on a net being torn down. Replacing with `disable_delayed_work_sync()` prevents new schedules. Trigger is network namespace teardown with xfrm NAT keepalive in use.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae,32d0f44c2f14d60fe8e920e69a28c11051543ec1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae,2255ed6adbc3100d2c4a83abd9d0396d04b87792)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae,21f2fc49ca6faa393c31da33b8a4e6c41fc84c13)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae,daf8e3b253aa760ff9e96c7768a464bc1d6b3c90)"}}], "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": "6.11"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.11)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.80,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.21,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.19.11,6.20.0)"}}, {"platform": null, "status": "unaffected", "versions": null}], "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"}], "created": "2026-04-06T20:14:56.247542+00:00", "updated": "2026-05-20T18:00:14.230698+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}