{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74581", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.918Z", "datePublished": "2026-08-21T16:31:54.683Z", "dateUpdated": "2026-10-16T19:05:58.061Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:07.594Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: clear suppressed fib6 rule result\n\nfib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(),\nbut leaves res->rt6 pointing at the released rt6_info.\n\nIf no later rule supplies a replacement, fib6_rule_lookup() still sees\nres.rt6 and returns that stale dst to its caller. A suppressing rule can\ntherefore leak a released route back to rt6_lookup(), and the next put\nhits rcuref_put_slowpath() from dst_release().\n\nClear res->rt6 when suppressing the route so suppressed lookups fall\nthrough to the null dst instead of reusing the released one." } ], "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 - fib6_rule_suppress() runs on every IPv6 route lookup via fib6_rule_lookup(), including ip6_route_input() for received packets and icmp6/icmpv6 redirect handlers; WireGuard/VPN servers commonly deploy suppress_prefixlength rules (wg-quick), so remote IPv6 traffic to those hosts reaches the bug.\nAC:L - Once suppress_prefixlength IPv6 policy routing rules exist, any matching packet deterministically triggers fib6_rule_suppress() to release the route while leaving a stale res->rt6 pointer; no race or uncontrollable memory layout is required.\nPR:N - Remote exploitation needs only the ability to send IPv6 packets through a host whose operator already configured suppress rules (e.g., wg-quick); CAP_NET_ADMIN is an admin deployment prerequisite, not attacker privilege on the target.\nUI:N - No victim action is required beyond normal delivery of attacker-generated IPv6 traffic (or ICMPv6 redirect) to a host performing policy-route lookup.\nS:U - The stale rt6_info/dst_entry UAF corrupts kernel heap memory within the same host security boundary; it is not a VM escape or cross-authority sandbox break.\nC:H - Returning a released rt6_info leaves a dangling dst_entry in ip6_dst_cache; subsequent reads through ip6_dst_idev(), dst metrics, or error paths are classic slab UAF with attacker-influencable heap reuse via sustained IPv6 traffic.\nI:H - Double-free/imbalanced rcuref put and post-free use of rt6_info fields give heap corruption primitives; UAF on dst/route cache objects is routinely leveraged for kernel write and control-flow hijack.\nA:H - Commit explicitly reports rcuref_put_slowpath() WARN from dst_release() on the freed route; UAF and refcount corruption can oops/panic the kernel, fully denying availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/fib6_rules.c" ], "versions": [ { "version": "209d35ee34e25f9668c404350a1c86d914c54ffa", "lessThan": "90c57310e266eb94e4a80d6b15a9ca131d2e82cb", "status": "affected", "versionType": "git" }, { "version": "8ef8a76a340ebdb2c2eea3f6fb0ebbed09a16383", "lessThan": "5d29b286c9de0b309e94b9ed083aa1a2f429434f", "status": "affected", "versionType": "git" }, { "version": "cdef485217d30382f3bf6448c54b4401648fe3f1", "lessThan": "354db6243eca59e9d187ffbf8b7955b044ce84dc", "status": "affected", "versionType": "git" }, { "version": "cdef485217d30382f3bf6448c54b4401648fe3f1", "lessThan": "6d98c70fe0ba8c7708bfd5b2a5174d2086775daa", "status": "affected", "versionType": "git" }, { "version": "cdef485217d30382f3bf6448c54b4401648fe3f1", "lessThan": "9bad152c42b37499162367fe47867411e62fffa3", "status": "affected", "versionType": "git" }, { "version": "cdef485217d30382f3bf6448c54b4401648fe3f1", "lessThan": "dc3ab04220667f254f4348572b2a0b3febff89fb", "status": "affected", "versionType": "git" }, { "version": "cdef485217d30382f3bf6448c54b4401648fe3f1", "lessThan": "a341c091ca0bfae377747b1b59a3bd8ebe18a937", "status": "affected", "versionType": "git" }, { "version": "cdef485217d30382f3bf6448c54b4401648fe3f1", "lessThan": "6aea62e433fe1b586202a5fee8b5807ce635e1d7", "status": "affected", "versionType": "git" }, { "version": "ee38eb8cf9a7323884c2b8e0adbbeb2192d31e29", "status": "affected", "versionType": "git" }, { "version": "5.10.84", "lessThan": "5.10.265", "status": "affected", "versionType": "semver" }, { "version": "5.15.7", "lessThan": "5.15.216", "status": "affected", "versionType": "semver" }, { "version": "5.4.164", "lessThan": "5.5", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/fib6_rules.c" ], "versions": [ { "version": "5.16", "status": "affected" }, { "version": "0", "lessThan": "5.16", "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": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "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": "5.10.84", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.7", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.6.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.164" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/90c57310e266eb94e4a80d6b15a9ca131d2e82cb" }, { "url": "https://git.kernel.org/stable/c/5d29b286c9de0b309e94b9ed083aa1a2f429434f" }, { "url": "https://git.kernel.org/stable/c/354db6243eca59e9d187ffbf8b7955b044ce84dc" }, { "url": "https://git.kernel.org/stable/c/6d98c70fe0ba8c7708bfd5b2a5174d2086775daa" }, { "url": "https://git.kernel.org/stable/c/9bad152c42b37499162367fe47867411e62fffa3" }, { "url": "https://git.kernel.org/stable/c/dc3ab04220667f254f4348572b2a0b3febff89fb" }, { "url": "https://git.kernel.org/stable/c/a341c091ca0bfae377747b1b59a3bd8ebe18a937" }, { "url": "https://git.kernel.org/stable/c/6aea62e433fe1b586202a5fee8b5807ce635e1d7" } ], "title": "net: ipv6: clear suppressed fib6 rule result", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74581", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:01:10.675016Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:58.061Z" } } ] } }