CVE-2026-80738

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80738", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.789Z", "datePublished": "2026-09-03T08:21:53.143Z", "dateUpdated": "2026-10-30T12:31:02.208Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:31:02.208Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie\n\nbpf_tcp_gen_syncookie and bpf_tcp_check_syncookie accept a socket pointer\n'sk' with argument type ARG_PTR_TO_BTF_ID_SOCK_COMMON. However, they access\nsk->sk_protocol without validating whether 'sk' represents a full socket.\n\nFix this issue by checking sk->sk_state != TCP_LISTEN before inspecting\nsk->sk_protocol in both bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie.\nSince mini-sockets are never in the TCP_LISTEN state, the condition\nshort-circuits and prevents dereferencing fullsock-specific fields."}], "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:L", "baseScore": 7.3, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The flaw is in bpf_tcp_gen_syncookie/bpf_tcp_check_syncookie BPF helpers invoked only from locally loaded and attached TC clsact or XDP programs via bpf(); per kernel CNA guidance BPF/tc paths are Local even when later triggered by ingress packets.\nAC:L - An attacker who loads the BPF program fully controls passing bpf_skc_lookup_tcp() results (request_sock/TCP_NEW_SYN_RECV or timewait sockets) into the syncookie helpers and can reliably trigger the bad sk_protocol read with crafted SYN/ACK traffic; no uncontrollable races or rare layout are required.\nPR:L - Exploitation requires bpf(BPF_PROG_LOAD) (CAP_BPF, obtainable in user namespaces) plus attaching TC/XDP hooks (CAP_NET_ADMIN via unshare -Urn); no init-namespace root is needed, matching CNA guidance for namespace-reachable net/BPF capabilities.\nUI:N - No victim mount, login, or cooperative action is required; once the attacker loads and attaches their BPF program, sending network packets from their own processes deterministically reaches the vulnerable helper on each matching lookup.\nS:U - Impact is confined to kernel heap disclosure/type confusion within the host kernel security domain; it does not cross VM, container runtime, IOMMU, or other security-authority boundaries.\nC:H - Casting a mini-socket to struct sock and reading sk_protocol performs a fixed-offset out-of-bounds read (~300+ bytes past request_sock/inet_timewait_sock) into adjacent slab memory, leaking kernel heap contents including pointers usable for further local exploitation.\nI:H - This is type confusion between ARG_PTR_TO_BTF_ID_SOCK_COMMON mini-sockets and full struct sock fields; per CNA guidance type confusion is rated High integrity impact even though the immediate bug is a read, because mis-typed socket pointers corrupt the kernel's object model.\nA:L - The primary impact is information disclosure; while the out-of-bounds u16 read usually stays within the slab page, reads near allocation boundaries or under KASAN can fault and oops the kernel, giving at least Low availability impact when uncertain."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/core/filter.c"], "versions": [{"version": "399040847084a69f345e0a52fd62f04654e0fce3", "lessThan": "b75f1c071f31be7f4b950721e04240c250091ad4", "status": "affected", "versionType": "git"}, {"version": "399040847084a69f345e0a52fd62f04654e0fce3", "lessThan": "5702e4c259809c760912c477c4ae34e9217bb4d9", "status": "affected", "versionType": "git"}, {"version": "399040847084a69f345e0a52fd62f04654e0fce3", "lessThan": "b5525e853a2a08a9559adb84b0616025958dc542", "status": "affected", "versionType": "git"}, {"version": "399040847084a69f345e0a52fd62f04654e0fce3", "lessThan": "22c2169770ad3b3595690e51caac875178cf496d", "status": "affected", "versionType": "git"}, {"version": "399040847084a69f345e0a52fd62f04654e0fce3", "lessThan": "23f682083aa3fbc0c49667818efd6979a8bc5ac2", "status": "affected", "versionType": "git"}, {"version": "399040847084a69f345e0a52fd62f04654e0fce3", "lessThan": "31a420a822ff92e2090bd5d65efe8e34e2d6d9b8", "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/core/filter.c"], "versions": [{"version": "5.2", "status": "affected"}, {"version": "0", "lessThan": "5.2", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "5.2", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.12.114"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.18.57"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b75f1c071f31be7f4b950721e04240c250091ad4"}, {"url": "https://git.kernel.org/stable/c/5702e4c259809c760912c477c4ae34e9217bb4d9"}, {"url": "https://git.kernel.org/stable/c/b5525e853a2a08a9559adb84b0616025958dc542"}, {"url": "https://git.kernel.org/stable/c/22c2169770ad3b3595690e51caac875178cf496d"}, {"url": "https://git.kernel.org/stable/c/23f682083aa3fbc0c49667818efd6979a8bc5ac2"}, {"url": "https://git.kernel.org/stable/c/31a420a822ff92e2090bd5d65efe8e34e2d6d9b8"}], "title": "bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/core/filter.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b75f1c071f31be7f4b950721e04240c250091ad4", "status": "affected", "version": "399040847084a69f345e0a52fd62f04654e0fce3", "versionType": "git"}, {"lessThan": "5702e4c259809c760912c477c4ae34e9217bb4d9", "status": "affected", "version": "399040847084a69f345e0a52fd62f04654e0fce3", "versionType": "git"}, {"lessThan": "b5525e853a2a08a9559adb84b0616025958dc542", "status": "affected", "version": "399040847084a69f345e0a52fd62f04654e0fce3", "versionType": "git"}, {"lessThan": "22c2169770ad3b3595690e51caac875178cf496d", "status": "affected", "version": "399040847084a69f345e0a52fd62f04654e0fce3", "versionType": "git"}, {"lessThan": "23f682083aa3fbc0c49667818efd6979a8bc5ac2", "status": "affected", "version": "399040847084a69f345e0a52fd62f04654e0fce3", "versionType": "git"}, {"lessThan": "31a420a822ff92e2090bd5d65efe8e34e2d6d9b8", "status": "affected", "version": "399040847084a69f345e0a52fd62f04654e0fce3", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/core/filter.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.2"}, {"lessThan": "5.2", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.114", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.57", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie\n\nbpf_tcp_gen_syncookie and bpf_tcp_check_syncookie accept a socket pointer\n'sk' with argument type ARG_PTR_TO_BTF_ID_SOCK_COMMON. However, they access\nsk->sk_protocol without validating whether 'sk' represents a full socket.\n\nFix this issue by checking sk->sk_state != TCP_LISTEN before inspecting\nsk->sk_protocol in both bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie.\nSince mini-sockets are never in the TCP_LISTEN state, the condition\nshort-circuits and prevents dereferencing fullsock-specific fields."}], "id": "CVE-2026-80738", "lastModified": "2026-10-30T13:20:10.940", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "LOW", "baseScore": 7.3, "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:L", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.5, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-03T13:06:12.910", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/22c2169770ad3b3595690e51caac875178cf496d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/23f682083aa3fbc0c49667818efd6979a8bc5ac2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/31a420a822ff92e2090bd5d65efe8e34e2d6d9b8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5702e4c259809c760912c477c4ae34e9217bb4d9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b5525e853a2a08a9559adb84b0616025958dc542"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b75f1c071f31be7f4b950721e04240c250091ad4"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[399040847084a69f345e0a52fd62f04654e0fce3,23f682083aa3fbc0c49667818efd6979a8bc5ac2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[399040847084a69f345e0a52fd62f04654e0fce3,31a420a822ff92e2090bd5d65efe8e34e2d6d9b8)"}}], "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": "generic", "value": "5.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.9,8.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "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": "2026-09-03T13:15:04.188404+00:00", "updated": "2026-09-04T06:30:14.810439+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-704"]}