{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74597", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.919Z", "datePublished": "2026-08-22T15:31:47.120Z", "dateUpdated": "2026-10-16T19:06:00.036Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:23.709Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: clear skb2->cb[] in ip6ip6_err()\n\nip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the\nquoted inner IPv6 packet, and then passes the clone to icmpv6_send().\nThe clone still carries the outer packet's inet6_skb_parm in skb->cb.\n\nIf the outer packet had a Home Address Option, IP6CB(skb2)->dsthao\nremains non-zero after skb_pull(). icmpv6_send() later calls\nmip6_addr_swap(), which uses that stale dsthao offset against the quoted\ninner packet. A malformed inner destination-options header can then make\nthe HAO lookup and address swap run past the end of the quoted packet\nand corrupt skb_shared_info.\n\nClear skb2->cb[] before pulling the quoted inner IPv6 packet so the\nreply path does not reuse metadata left by the outer IPv6 stack." } ], "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 when a remote peer sends a forged ICMPv6 error whose quoted payload is an IPv6-in-IPv6 tunnel datagram; processing follows the normal IPv6 receive path (ipv6_rcv -> icmpv6_notify -> tunnel6_err -> ip6ip6_err) with no local access required.\nAC:L - The attacker controls the carrier IPv6 Home Address Option, quoted tunnel/inner headers, and ICMP error type; once an ip6tnl endpoint exists (normal for this subsystem), triggering the stale-dsthao path is reliable and needs no races or victim interaction.\nPR:N - No authentication or capabilities are required on the target; unprivileged remote senders can deliver crafted ICMPv6 errors that the kernel processes on the standard pre-auth receive path (INET6_PROTO_NOPOLICY).\nUI:N - Exploitation requires only delivering a malicious network packet; no victim must open files, click links, or perform any other action.\nS:U - Impact is in-kernel memory corruption on the receiving host within the same security authority; it does not by itself cross VM, container, or IOMMU boundaries.\nC:H - With CONFIG_IPV6_MIP6, mip6_addr_swap() uses the stale dsthao offset to scan the quoted inner packet and can read attacker-controlled bytes past the skb tail while resolving a fake HAO TLV before swapping addresses.\nI:H - The resulting 16-byte swap(iph->saddr, hao->addr) can write beyond the quoted packet into skb_shared_info, giving attacker-influenced heap corruption suitable for further control-flow or data manipulation.\nA:H - Corrupting skb_shared_info from the network input path can cause kernel oops/panic or otherwise deny service on IPv6 tunnel endpoints, and the condition is repeatable with crafted packets." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_tunnel.c" ], "versions": [ { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "44fe898df302e91c5ee5acbc71ffa74e78e6c183", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "0dadb0620ab65949a8bc2439dd28ea3c942fe87d", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "b6816536a2990c0db44a26130a03e40b441e829b", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "64e41736a26f37ab6215bc2e6df125df05aceb08", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "484134e1eb07d700a73b1e4bbf3fb503e299be60", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "4eb15c465337b18f44716c499cd6ad63eee0ad54", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "fbf40faa0414b753212494ad197542002e66ed9e", "status": "affected", "versionType": "git" }, { "version": "e490d1d85cf5e191791979e5f260d32eb4f703a8", "lessThan": "f803c086399da277b5d0ff36a107d0f162751800", "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/ip6_tunnel.c" ], "versions": [ { "version": "2.6.22", "status": "affected" }, { "version": "0", "lessThan": "2.6.22", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "2.6.22", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/44fe898df302e91c5ee5acbc71ffa74e78e6c183" }, { "url": "https://git.kernel.org/stable/c/0dadb0620ab65949a8bc2439dd28ea3c942fe87d" }, { "url": "https://git.kernel.org/stable/c/b6816536a2990c0db44a26130a03e40b441e829b" }, { "url": "https://git.kernel.org/stable/c/64e41736a26f37ab6215bc2e6df125df05aceb08" }, { "url": "https://git.kernel.org/stable/c/484134e1eb07d700a73b1e4bbf3fb503e299be60" }, { "url": "https://git.kernel.org/stable/c/4eb15c465337b18f44716c499cd6ad63eee0ad54" }, { "url": "https://git.kernel.org/stable/c/fbf40faa0414b753212494ad197542002e66ed9e" }, { "url": "https://git.kernel.org/stable/c/f803c086399da277b5d0ff36a107d0f162751800" } ], "title": "ip6_tunnel: clear skb2->cb[] in ip6ip6_err()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74597", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:01:48.402907Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:06:00.036Z" } } ] } }