{"id":"CVE-2026-31680","revision":null,"records":[{"revision":"4da3c4a51f064d5994cbfb8cb35a8377","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31680","aliases":[],"title":"net: ipv6: flowlabel: defer exclusive option free until RCU teardown","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: flowlabel: defer exclusive option free until RCU teardown\n\n`ip6fl_seq_show()` walks the global flowlabel hash under the seq-file\nRCU read-side lock and prints `fl->opt->opt_nflen` when an option block\nis present.\n\nExclusive flowlabels currently free `fl->opt` as soon as `fl->users`\ndrops to zero in `fl_release()`. However, the surrounding\n`struct ip6_flowlabel` remains visible in the global hash table until\nlater garbage collection removes it and `fl_free_rcu()` finally tears it\ndown.\n\nA concurrent `/proc/net/ip6_flowlabel` reader can therefore race that\nearly `kfree()` and dereference freed option state, triggering a crash\nin `ip6fl_seq_show()`.\n\nFix this by keeping `fl->opt` alive until `fl_free_rcu()`. That matches\nthe lifetime already required for the enclosing flowlabel while readers\ncan still reach it under RCU.","state":0,"publishedAt":"2026-04-25T08:46:56.807+00:00","modifiedAt":"2026-10-19T18:56:04.513+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/ipv6/ip6_flowlabel.c\"\n ],\n \"versions\": [\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"4b6798024f7b2d535f3db1002c760143cdbd1bd3\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"3c54b66c83fb8fcbde8e6a7bf90b65856e39f827\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"5a6b15f861b7c1304949e3350d23490a5fe429fd\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"6c7fbdb8ffde6413640de7cfbd7c976c353e89f8\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"8027964931785cb73d520ac70a342a3dc16c249b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"414726b69921fe6355ae453f5b35e68dd078342a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"572ce62778519a7d4d1c15f55dd2e45a474133c4\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3aedd5ebd4b0b925b0bcda548066803e1318499\",\n \"lessThan\": \"9ca562bb8e66978b53028fa32b1a190708e6a091\",\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/ipv6/ip6_flowlabel.c\"\n ],\n \"versions\": [\n {\n \"version\": \"3.9\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"3.9\",\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\": \"6.6.134\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.81\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.22\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.19.12\",\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/4b6798024f7b2d535f3db1002c760143cdbd1bd3","https://git.kernel.org/stable/c/3c54b66c83fb8fcbde8e6a7bf90b65856e39f827","https://git.kernel.org/stable/c/5a6b15f861b7c1304949e3350d23490a5fe429fd","https://git.kernel.org/stable/c/6c7fbdb8ffde6413640de7cfbd7c976c353e89f8","https://git.kernel.org/stable/c/8027964931785cb73d520ac70a342a3dc16c249b","https://git.kernel.org/stable/c/414726b69921fe6355ae453f5b35e68dd078342a","https://git.kernel.org/stable/c/572ce62778519a7d4d1c15f55dd2e45a474133c4","https://git.kernel.org/stable/c/9ca562bb8e66978b53028fa32b1a190708e6a091"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31680","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31680","identifiers":["CVE-2026-31680"]},"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. Not a global EPSS backfill.","generation":"2026-11-08T21:02:31.8931850+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-08T21:02:31.893185+00:00","lastSuccessAt":"2026-11-08T21:02:32.3894193+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:32.38942+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-ddc095a411c54633beb68aaff30b70cb","complete":true,"records":13666,"lastAttemptAt":"2026-11-08T21:02:34.4952279+00:00","lastSuccessAt":"2026-11-08T21:02:34.481+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:34.481+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-08T21:02:31.7841816+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.7841816+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-08T21:02:31.5325642+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.5325642+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-964c14035e6f0f6478b2870fad6a7ef9f6045876d4a12af2c2e514521e54b6af","complete":true,"records":3055,"lastAttemptAt":"2026-11-08T21:02:31.8040207+00:00","lastSuccessAt":"2026-11-08T11:07:12.1927025+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.8040207+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f8647d7ba64b1ba0dfdc7130944766d5b36d5b77d18fff0c79e651a4cff3c2b9","complete":true,"records":231293,"lastAttemptAt":"2026-11-08T21:02:31.6506398+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.6506398+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}