{"id":"CVE-2026-89563","revision":null,"records":[{"revision":"88baec989c4b49f08e8c89055990f146","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89563","aliases":[],"title":"ip6_tunnel: use skb_cow_head() in ip6_tnl_xmit()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: use skb_cow_head() in ip6_tnl_xmit()\n\nip6_tnl_xmit() may need to expand headroom before it can push the\nouter IPv6 and optional encap headers. It currently does that with\nskb_realloc_headroom(), copies skb->sk ownership, consumes the original\nskb, and then continues processing with the replacement skb kept only in\nits local variable.\n\nThat is safe only if the helper cannot fail afterwards. But this helper\nstill has post-reallocation error exits. collect_md tunnels reject\nnon-NONE encap after the replacement, and ip6_tnl_encap() can also fail\nlater. In those cases the helper returns an error to its callers while\nthe caller still only has the original skb pointer.\n\nBoth ip6_tnl_start_xmit() and the IPv6 GRE paths free the caller skb on\nerror, so they can end up freeing an skb that ip6_tnl_xmit() already\nconsumed.\n\nUse skb_cow_head() instead. It provides the required headroom and\nwritability without privately replacing the caller-owned skb, so later\nerror returns cannot leave callers with a stale pointer.\n\nThe Ethernet users, ip6gretap and ip6erspan, clear IFF_TX_SKB_SHARING\nand already call skb_cow_head() before entering ip6_tnl_xmit(). They do\nnot rely on the removed skb_shared() reallocation. This also makes the\nIPv6 tunnel path consistent with ip_tunnel_xmit().","state":0,"publishedAt":"2026-09-11T19:44:34.375+00:00","modifiedAt":"2026-10-19T08:48:56.784+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_tunnel.c\"\n ],\n \"versions\": [\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"6e8eff8ed13b14708bc39f170144eacde494aac6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"dc1a319a4815c074914e2812e0e9cd0164ca682b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"629d5557e635cdbc109a14ed913ba5a540e3f79a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"defa0adeff132cc90ed66915b9a104d9393e1e54\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"37df5bc6b5ccad88c2faa0f5466f150178882b74\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"b36dfd6e8cff00cea81c11cc0af88d1564763461\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"8fc56ca49fc0ee1725b55c67bb43ab0dd01f3f52\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"058214a4d1dfefed9f01a277fadd3590acb5f990\",\n \"lessThan\": \"87f21b59ddc618eff9670c174842964ad65fdade\",\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_tunnel.c\"\n ],\n \"versions\": [\n {\n \"version\": \"4.7\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"4.7\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.270\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.221\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.188\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.157\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.109\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.50\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.4\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\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/6e8eff8ed13b14708bc39f170144eacde494aac6","https://git.kernel.org/stable/c/dc1a319a4815c074914e2812e0e9cd0164ca682b","https://git.kernel.org/stable/c/629d5557e635cdbc109a14ed913ba5a540e3f79a","https://git.kernel.org/stable/c/defa0adeff132cc90ed66915b9a104d9393e1e54","https://git.kernel.org/stable/c/37df5bc6b5ccad88c2faa0f5466f150178882b74","https://git.kernel.org/stable/c/b36dfd6e8cff00cea81c11cc0af88d1564763461","https://git.kernel.org/stable/c/8fc56ca49fc0ee1725b55c67bb43ab0dd01f3f52","https://git.kernel.org/stable/c/87f21b59ddc618eff9670c174842964ad65fdade"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89563","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89563","identifiers":["CVE-2026-89563"]},"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-4f2cebce00d8473081b28b769c5ae383","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T05:14:17.7698071+00:00","lastSuccessAt":"2026-11-09T05:14:17.765+00:00","error":"8 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-09T05:14:17.765+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13657,"expectedIdentifiers":13706,"failedIdentifiers":8},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T05:02:23.3236319+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T05:02:23.3236319+00:00","lastSuccessAt":"2026-11-09T05:02:23.4802497+00:00","error":null,"lastVerifiedAt":"2026-11-09T05:02:23.4802499+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-5a44a451442747cb81d83104fe1e7771","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T05:02:23.9456768+00:00","lastSuccessAt":"2026-11-09T02:08:52.274+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:52.274+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":"2026-11-09T05:02:15.1760519+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T05:02:15.1760519+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":"2026-11-09T05:02:14.6871775+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T05:02:14.6871775+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-f6d341f4320a5a0c059c28102ee651c3dd06abc87b84d2bafa4e2a823ec07d35","complete":true,"records":3056,"lastAttemptAt":"2026-11-09T05:02:23.2913664+00:00","lastSuccessAt":"2026-11-09T05:02:23.1539412+00:00","error":null,"lastVerifiedAt":"2026-11-09T05:02:23.2913664+00:00","snapshotPublishedAt":"2026-11-09T04:47:48+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-6a1c845b1938b1aa788f0e95c9ac8a8d5a1f07caed5d155840b0616b548c1455","complete":true,"records":231296,"lastAttemptAt":"2026-11-09T05:02:15.0730779+00:00","lastSuccessAt":"2026-11-09T04:03:49.859595+00:00","error":null,"lastVerifiedAt":"2026-11-09T05:02:15.0730779+00:00","snapshotPublishedAt":"2026-11-09T03:33:06+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}