{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63922","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T07:54:57.021Z","datePublished":"2026-07-19T14:55:24.268Z","dateUpdated":"2026-08-05T12:37:16.967Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:37:16.967Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: exthdrs: refresh nh after handling HAO option\n\nip6_parse_tlv() caches skb_network_header(skb) in nh while walking\nIPv6 TLVs.\n\nipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can\nmove the skb head and invalidate the cached network header pointer.\nRefresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs\nare parsed from the current skb head.\n\nThis matches the existing pattern used in ip6_parse_tlv() after helpers\nthat can modify skb header storage."}],"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 reached on the standard IPv6 input path (ipv6_rcv → ip6_input → ip6_protocol_deliver_rcu → ipv6_destopt_rcv) when a remotely sent IPv6 packet carries a Destination Options header processed by ip6_parse_tlv().\nAC:L - The attacker fully controls the crafted IPv6 Destination Options layout (HAO TLV followed by trailing TLVs/padding); once CONFIG_IPV6_MIP6 and matching XFRM state exist on the target, triggering the stale-pointer condition is a reliable single-packet attack without races or victim-specific timing.\nPR:N - No local privileges or authentication are required; any remote host that can deliver IPv6 traffic to a listening interface can reach this pre-authentication receive-path parser (destopt_protocol uses INET6_PROTO_NOPOLICY).\nUI:N - Exploitation requires only sending a malicious IPv6 packet; no victim interaction such as opening files, clicking links, or mounting filesystems is needed.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the kernel’s security authority; it does not cross VM, container, or IOMMU boundaries.\nC:H - After pskb_expand_head() frees the old skb head, ip6_parse_tlv() continues parsing trailing TLVs through the stale nh pointer, causing out-of-bounds/use-after-free reads of kernel heap memory that can disclose sensitive kernel data.\nI:H - Use-after-free of the skb head buffer during TLV parsing is heap memory corruption that can be leveraged for arbitrary kernel writes and control-flow hijacking, not merely a bounded parse error.\nA:H - Reading through the stale network-header pointer into freed or invalid memory can cause kernel oops/panic or unrecoverable instability, satisfying high availability impact even before full exploitation."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/exthdrs.c"],"versions":[{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"b3ac54e5c905f86d22b502eacb5686a282c5659f","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"f8aabed3ff3e986920cf02a2a2785e08e586b234","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"12d957979e4a800167842f1b42be6a606d227ebe","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"ff375ed1cba81392346c5bfbf0bb7a13b2946f99","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"751db1b802a067b7fff25880f4e9f9152a171538","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"9b6dcc0a39fd71752937f0b6b3973e1416085dcf","status":"affected","versionType":"git"},{"version":"a831f5bbc89a9978795504be9e1ff412043f8f77","lessThan":"f7b52afe3592eae66e160586b45a3f2242972c63","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/exthdrs.c"],"versions":[{"version":"2.6.19","status":"affected"},{"version":"0","lessThan":"2.6.19","status":"unaffected","versionType":"semver"},{"version":"5.10.259","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.210","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.176","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.143","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.93","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.35","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.12","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f"},{"url":"https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234"},{"url":"https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1"},{"url":"https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe"},{"url":"https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99"},{"url":"https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538"},{"url":"https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf"},{"url":"https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63"}],"title":"ipv6: exthdrs: refresh nh after handling HAO option","x_generator":{"engine":"bippy-1.2.0"}}}}