{"id":"CVE-2026-80792","state":"PUBLISHED","title":"ipv6: fix use-after-free in ip6_finish_output2()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix use-after-free in ip6_finish_output2()\n\nip6_finish_output2() caches a pointer to the IPv6 destination\naddress (daddr) before invoking lwtunnel_xmit().  The LWT-BPF\ntransmit path or other encapsulation operations within\nlwtunnel_xmit() can reallocate the skb head, freeing the memory\nthat daddr points to.  When lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, the function continues to use the stale\ndaddr pointer to compute the nexthop and to look up or create the\nneighbour entry.  This results in a use-after-free read, which can\nleak sensitive kernel data, pollute the neighbour table with\narbitrary values, misdirect traffic, or crash the system.\n\nFix this by re-fetching the IPv6 header and the destination\naddress pointer after lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop\ncomputation and neighbour lookup operate on valid memory.","publishedAt":"2026-09-04T15:13:04.537Z","updatedAt":"2026-10-19T08:43:45.535Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4132c4ad00ddbf3a175ea0d2c775b662a32f4c85","status":"affected","lessThan":"75e0a544ebe9af663ef53ca21e9e9185c51fb54a","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"c95f01b78266828a57060d754fcbfc92123a98ed","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"d960881b9312e781a3429aabceb223ce6b7c882f","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"087ee0d914aaae929f1660c9ca878e367655ba1a","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"3c770ac4e6f07af7c7b40c474a3efc61ffed7862","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"3dc98e5fe82d069dd29b124ffbdb679331dfea43","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"99219c82804f266189388e8bf1cf5135d10d5515","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"73a187384a8c8b983c7fea046d716b6752a1e7a3","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"d0d48d999b0eee6bb176ef4e39d9be868fa80f7e","versionType":"git"},{"version":"1598154fd28ffa4a55beae1970475fd6776554b6","status":"affected","versionType":"git"},{"version":"5.10.233","status":"affected","lessThan":"5.10.267","versionType":"semver"},{"version":"5.4.289","status":"affected","lessThan":"5.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.10.267","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.218","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.185","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.154","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.106","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.47","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.11","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.1","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]}],"references":["https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a","https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed","https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f","https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a","https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862","https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43","https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515","https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3","https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80792.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80792","state":"PUBLISHED","datePublished":"2026-09-04T15:13:04.537Z","dateUpdated":"2026-10-19T08:43:45.535Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.793Z"},"containers":{"cna":{"title":"ipv6: fix use-after-free in ip6_finish_output2()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix use-after-free in ip6_finish_output2()\n\nip6_finish_output2() caches a pointer to the IPv6 destination\naddress (daddr) before invoking lwtunnel_xmit().  The LWT-BPF\ntransmit path or other encapsulation operations within\nlwtunnel_xmit() can reallocate the skb head, freeing the memory\nthat daddr points to.  When lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, the function continues to use the stale\ndaddr pointer to compute the nexthop and to look up or create the\nneighbour entry.  This results in a use-after-free read, which can\nleak sensitive kernel data, pollute the neighbour table with\narbitrary values, misdirect traffic, or crash the system.\n\nFix this by re-fetching the IPv6 header and the destination\naddress pointer after lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop\ncomputation and neighbour lookup operate on valid memory."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4132c4ad00ddbf3a175ea0d2c775b662a32f4c85","status":"affected","lessThan":"75e0a544ebe9af663ef53ca21e9e9185c51fb54a","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"c95f01b78266828a57060d754fcbfc92123a98ed","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"d960881b9312e781a3429aabceb223ce6b7c882f","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"087ee0d914aaae929f1660c9ca878e367655ba1a","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"3c770ac4e6f07af7c7b40c474a3efc61ffed7862","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"3dc98e5fe82d069dd29b124ffbdb679331dfea43","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"99219c82804f266189388e8bf1cf5135d10d5515","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"73a187384a8c8b983c7fea046d716b6752a1e7a3","versionType":"git"},{"version":"e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2","status":"affected","lessThan":"d0d48d999b0eee6bb176ef4e39d9be868fa80f7e","versionType":"git"},{"version":"1598154fd28ffa4a55beae1970475fd6776554b6","status":"affected","versionType":"git"},{"version":"5.10.233","status":"affected","lessThan":"5.10.267","versionType":"semver"},{"version":"5.4.289","status":"affected","lessThan":"5.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.10.267","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.218","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.185","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.154","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.106","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.47","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.11","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.1","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a"},{"url":"https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed"},{"url":"https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f"},{"url":"https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a"},{"url":"https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862"},{"url":"https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43"},{"url":"https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515"},{"url":"https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3"},{"url":"https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:43:45.535Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.233","versionEndExcluding":"5.10.267"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"5.15.218"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.185"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.6.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.106"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.1.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kerne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