{"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":"2026-08-25T05:40:07.594Z"},"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"}}}}