{"id":"CVE-2026-63924","state":"PUBLISHED","title":"ipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo()\n\nipv6_hop_jumbo() calls pskb_trim_rcsum(), which can change skb pointers.\nLet's recompute nh pointer to make sure any change won't mess things up.","publishedAt":"2026-07-19T14:55:25.702Z","updatedAt":"2026-10-19T20:17:56.915Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b3ac54e5c905f86d22b502eacb5686a282c5659f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"645b99b1a185c91a79bdac4c5de0f91b212d64f0","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9e883eaa878f4337b5873c706efb5a192364ed18","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"bddaa4dfc7f36e1ee343a0622f69288af2b9ace9","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"72af7beae774e46ed543f3f2f267bf0a141bfcdd","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"c512e1c819dfbf6ae95ee7a44b65b9ad98979157","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2b56bbd928c030894c270cd33d60286326919458","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"d47548a36639095939f4747d4c43f2271366f565","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/exthdrs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/exthdrs.c"]}],"references":["https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f","https://git.kernel.org/stable/c/645b99b1a185c91a79bdac4c5de0f91b212d64f0","https://git.kernel.org/stable/c/9e883eaa878f4337b5873c706efb5a192364ed18","https://git.kernel.org/stable/c/bddaa4dfc7f36e1ee343a0622f69288af2b9ace9","https://git.kernel.org/stable/c/72af7beae774e46ed543f3f2f267bf0a141bfcdd","https://git.kernel.org/stable/c/c512e1c819dfbf6ae95ee7a44b65b9ad98979157","https://git.kernel.org/stable/c/2b56bbd928c030894c270cd33d60286326919458","https://git.kernel.org/stable/c/d47548a36639095939f4747d4c43f2271366f565"],"weaknesses":["CWE-822"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63924.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63924","state":"PUBLISHED","datePublished":"2026-07-19T14:55:25.702Z","dateUpdated":"2026-10-19T20:17:56.915Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.021Z"},"containers":{"cna":{"title":"ipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo()\n\nipv6_hop_jumbo() calls pskb_trim_rcsum(), which can change skb pointers.\nLet's recompute nh pointer to make sure any change won't mess things up."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b3ac54e5c905f86d22b502eacb5686a282c5659f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"645b99b1a185c91a79bdac4c5de0f91b212d64f0","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9e883eaa878f4337b5873c706efb5a192364ed18","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"bddaa4dfc7f36e1ee343a0622f69288af2b9ace9","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"72af7beae774e46ed543f3f2f267bf0a141bfcdd","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"c512e1c819dfbf6ae95ee7a44b65b9ad98979157","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2b56bbd928c030894c270cd33d60286326919458","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"d47548a36639095939f4747d4c43f2271366f565","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/exthdrs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/exthdrs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f"},{"url":"https://git.kernel.org/stable/c/645b99b1a185c91a79bdac4c5de0f91b212d64f0"},{"url":"https://git.kernel.org/stable/c/9e883eaa878f4337b5873c706efb5a192364ed18"},{"url":"https://git.kernel.org/stable/c/bddaa4dfc7f36e1ee343a0622f69288af2b9ace9"},{"url":"https://git.kernel.org/stable/c/72af7beae774e46ed543f3f2f267bf0a141bfcdd"},{"url":"https://git.kernel.org/stable/c/c512e1c819dfbf6ae95ee7a44b65b9ad98979157"},{"url":"https://git.kernel.org/stable/c/2b56bbd928c030894c270cd33d60286326919458"},{"url":"https://git.kernel.org/stable/c/d47548a36639095939f4747d4c43f2271366f565"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The bug is in the IPv6 input path (ipv6_rcv → ip6_rcv_core → ipv6_parse_hopopts) triggered by a crafted IPv6 packet with hop-by-hop options containing a Jumbo Payload TLV, reachable from any remote peer that can deliver IPv6 to the host.\nAC:L - An attacker fully controls the crafted IPv6 packet (HBH layout, jumbo length, trailing TLVs) and can send it repeatedly; once the skb is cloned/shared during receive and pskb_trim_rcsum reallocates the head, the stale-pointer UAF is deterministically triggered without races or victim-specific state.\nPR:N - No authentication or local privileges are required; any unauthenticated remote host that can send IPv6 traffic to a listening interface reaches the vulnerable receive handler with no capability or namespace checks along the path.\nUI:N - Exploitation requires only delivery of a malicious IPv6 packet and does not depend on any victim user action such as opening files, clicking links, or mounting filesystems.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the same kernel security domain; it does not cross a VM, container, or IOMMU boundary by itself.\nC:H - Continued HBH TLV parsing through the stale nh pointer is a use-after-free read of freed skb head memory, which per kernel guidance enables arbitrary kernel memory disclosure when the freed slab is reused.\nI:H - Stale-pointer UAF during TLV length/type parsing can yield unbounded out-of-bounds reads and corrupt subsequent parsing state, providing memory corruption primitives that can be developed into arbitrary kernel writes or code execution.\nA:H - Dereferencing the freed network-header pointer during TLV parsing can cause immediate kernel oops/panic from invalid memory access, and UAF-triggered parsing errors reliably drop or crash the receive path."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:37:19.118Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63924","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:33:33.023391Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-822","lang":"en","type":"CWE","description":"CWE-822 Untrusted Pointer Dereference"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:17:56.915Z"}}]}}}