{"api_version":"1","generated_at":"2026-04-23T01:19:07+00:00","cve":"CVE-2026-31495","urls":{"html":"https://cve.report/CVE-2026-31495","api":"https://cve.report/api/cve/CVE-2026-31495.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31495","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31495"},"summary":{"title":"netfilter: ctnetlink: use netlink policy range checks","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range checks\n\nReplace manual range and mask validations with netlink policy\nannotations in ctnetlink code paths, so that the netlink core rejects\ninvalid values early and can generate extack errors.\n\n- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at\n  policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE\n  (14). The normal TCP option parsing path already clamps to this value,\n  but the ctnetlink path accepted 0-255, causing undefined behavior when\n  used as a u32 shift count.\n- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with\n  CTA_FILTER_F_ALL, removing the manual mask checks.\n- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding\n  a new mask define grouping all valid expect flags.\n\nExtracted from a broader nf-next patch by Florian Westphal, scoped to\nctnetlink for the fixes tree.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-22 14:16:47","updated_at":"2026-04-22 14:16:47"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5","name":"https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292","name":"https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804","name":"https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6","name":"https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474","name":"https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b","name":"https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3","name":"https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704","name":"https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31495","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31495","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 435b576cd2faa75154777868f8cbb73bf71644d3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 2ef71307c86a9f866d6e28f1a0c06e2e9d794474 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 4f7d25f3f0786402ba48ff7d13b6241d77d975f5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 fcec5ce2d73a41668b24e3f18c803541602a59f6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.168 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.131 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.80 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.21 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.11 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/uapi/linux/netfilter/nf_conntrack_common.h","net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_proto_tcp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"435b576cd2faa75154777868f8cbb73bf71644d3","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"2ef71307c86a9f866d6e28f1a0c06e2e9d794474","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"4f7d25f3f0786402ba48ff7d13b6241d77d975f5","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"fcec5ce2d73a41668b24e3f18c803541602a59f6","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"675c913b940488a84effdeeac5a1cfb657b59804","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"c6cb41eaae875501eaaa487b8db6539feb092292","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"45c33e79ae705b7af97e3117672b6cd258dd0b1b","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"},{"lessThan":"8f15b5071b4548b0aafc03b366eb45c9c6566704","status":"affected","version":"c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/uapi/linux/netfilter/nf_conntrack_common.h","net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_proto_tcp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.22"},{"lessThan":"2.6.22","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.168","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.131","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"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.168","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.131","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.80","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.21","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.11","versionStartIncluding":"2.6.22","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"2.6.22","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range checks\n\nReplace manual range and mask validations with netlink policy\nannotations in ctnetlink code paths, so that the netlink core rejects\ninvalid values early and can generate extack errors.\n\n- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at\n  policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE\n  (14). The normal TCP option parsing path already clamps to this value,\n  but the ctnetlink path accepted 0-255, causing undefined behavior when\n  used as a u32 shift count.\n- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with\n  CTA_FILTER_F_ALL, removing the manual mask checks.\n- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding\n  a new mask define grouping all valid expect flags.\n\nExtracted from a broader nf-next patch by Florian Westphal, scoped to\nctnetlink for the fixes tree."}],"providerMetadata":{"dateUpdated":"2026-04-22T13:54:17.591Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3"},{"url":"https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474"},{"url":"https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5"},{"url":"https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6"},{"url":"https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804"},{"url":"https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292"},{"url":"https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b"},{"url":"https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704"}],"title":"netfilter: ctnetlink: use netlink policy range checks","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31495","datePublished":"2026-04-22T13:54:17.591Z","dateReserved":"2026-03-09T15:48:24.102Z","dateUpdated":"2026-04-22T13:54:17.591Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-22 14:16:47","lastModifiedDate":"2026-04-22 14:16:47","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31495","Ordinal":"1","Title":"netfilter: ctnetlink: use netlink policy range checks","CVE":"CVE-2026-31495","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31495","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range checks\n\nReplace manual range and mask validations with netlink policy\nannotations in ctnetlink code paths, so that the netlink core rejects\ninvalid values early and can generate extack errors.\n\n- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at\n  policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE\n  (14). The normal TCP option parsing path already clamps to this value,\n  but the ctnetlink path accepted 0-255, causing undefined behavior when\n  used as a u32 shift count.\n- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with\n  CTA_FILTER_F_ALL, removing the manual mask checks.\n- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding\n  a new mask define grouping all valid expect flags.\n\nExtracted from a broader nf-next patch by Florian Westphal, scoped to\nctnetlink for the fixes tree.","Type":"Description","Title":"netfilter: ctnetlink: use netlink policy range checks"}]}}}