{"id":"CVE-2026-31504","revision":null,"records":[{"revision":"978edd9616b14da1a33f2d3863243823","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31504","aliases":[],"title":"net: fix fanout UAF in packet_release() via NETDEV_UP race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fix fanout UAF in packet_release() via NETDEV_UP race\n\n`packet_release()` has a race window where `NETDEV_UP` can re-register a\nsocket into a fanout group's `arr[]` array. The re-registration is not\ncleaned up by `fanout_release()`, leaving a dangling pointer in the fanout\narray.\n`packet_release()` does NOT zero `po->num` in its `bind_lock` section.\nAfter releasing `bind_lock`, `po->num` is still non-zero and `po->ifindex`\nstill matches the bound device. A concurrent `packet_notifier(NETDEV_UP)`\nthat already found the socket in `sklist` can re-register the hook.\nFor fanout sockets, this re-registration calls `__fanout_link(sk, po)`\nwhich adds the socket back into `f->arr[]` and increments `f->num_members`,\nbut does NOT increment `f->sk_ref`.\n\nThe fix sets `po->num` to zero in `packet_release` while `bind_lock` is\nheld to prevent NETDEV_UP from linking, preventing the race window.\n\nThis bug was found following an additional audit with Claude Code based\non CVE-2025-38617.","state":0,"publishedAt":"2026-04-22T13:54:23.862+00:00","modifiedAt":"2026-10-19T18:45:53.946+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/packet/af_packet.c\"\n ],\n \"versions\": [\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"ee642b1962caa9aa231c01abbd58bc453ae6b66e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"42cfd7898eeed290c9fb73f732af1f7d6b0a703e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"1b4c03f8892d955385c202009af7485364731bb9\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"654386baef228c2992dbf604c819e4c7c35fc71b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"75fe6db23705a1d55160081f7b37db9665b1880b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"d0c7cdc15fdf8c4f91aca1928e52295d175b6ec6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"ceccbfc6de720ad633519a226715989cfb065af1\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ce06b03e60fc19c680d1bf873e779bf11c2fc518\",\n \"lessThan\": \"42156f93d123436f2a27c468f18c966b7e5db796\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/packet/af_packet.c\"\n ],\n \"versions\": [\n {\n \"version\": \"3.1\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"3.1\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.253\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.203\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.168\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.131\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.80\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.21\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.19.11\",\n \"lessThanOrEqual\": \"6.19.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.0\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/ee642b1962caa9aa231c01abbd58bc453ae6b66e","https://git.kernel.org/stable/c/42cfd7898eeed290c9fb73f732af1f7d6b0a703e","https://git.kernel.org/stable/c/1b4c03f8892d955385c202009af7485364731bb9","https://git.kernel.org/stable/c/654386baef228c2992dbf604c819e4c7c35fc71b","https://git.kernel.org/stable/c/75fe6db23705a1d55160081f7b37db9665b1880b","https://git.kernel.org/stable/c/d0c7cdc15fdf8c4f91aca1928e52295d175b6ec6","https://git.kernel.org/stable/c/ceccbfc6de720ad633519a226715989cfb065af1","https://git.kernel.org/stable/c/42156f93d123436f2a27c468f18c966b7e5db796"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31504","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31504","identifiers":["CVE-2026-31504"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-45d47722bca14f09ac26662adb699591","complete":true,"records":13654,"lastAttemptAt":"2026-11-08T21:02:36.7086981+00:00","lastSuccessAt":"2026-11-08T20:47:46.939+00:00","error":null,"lastVerifiedAt":"2026-11-08T20:47:46.939+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. 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