{"api_version":"1","generated_at":"2026-09-12T08:47:37+00:00","cve":"CVE-2026-80995","urls":{"html":"https://cve.report/CVE-2026-80995","api":"https://cve.report/api/cve/CVE-2026-80995.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80995","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80995"},"summary":{"title":"net: mctp: hold a reference to the route device in mctp_route_lookup()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mctp: hold a reference to the route device in mctp_route_lookup()\n\nmctp_route_lookup() uses rt->dev without holding a reference on it.\nmctp_route_lookup_single() returns the route under RCU only, so the\nroute's device can be torn down concurrently: mctp_dev_put() drops the\nlast reference and synchronously kfree()s mdev->addrs.  mctp_dev_saddr()\nthen reads rt->dev->addrs[0], giving a use-after-free reachable by an\nunprivileged local AF_MCTP user on the receive/forwarding path (no\nCAP_NET_RAW required):\n\n  BUG: KASAN: slab-use-after-free in mctp_route_lookup\n  Read of size 1 at addr ... by task mctp_uaf/...\n   mctp_route_lookup\n   mctp_pkttype_receive\n  Freed by task ...:\n   kfree\n   mctp_dev_put\n   mctp_dev_notify\n\nIn the same window mctp_dst_from_route() -> mctp_dev_hold() also\nincrements a refcount that has already reached zero\n(\"refcount_t: addition on 0 ... mctp_dev_hold\").\n\nThis reintroduces the use-after-free class of CVE-2023-3439: the source\naddress lookup was moved ahead of the point where the destination takes\nits device reference.\n\nTake a reference with refcount_inc_not_zero() before touching rt->dev,\nskip a device that is already dead, and drop the reference once the\ndestination has taken its own.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:06","updated_at":"2026-09-11 20:19:06"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/cc561f8af25586300c2f9d285babb163b866b293","name":"https://git.kernel.org/stable/c/cc561f8af25586300c2f9d285babb163b866b293","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/408da1df18116c971c3392e21e50586688cd3fbf","name":"https://git.kernel.org/stable/c/408da1df18116c971c3392e21e50586688cd3fbf","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80995","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80995","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1 cc561f8af25586300c2f9d285babb163b866b293 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1 408da1df18116c971c3392e21e50586688cd3fbf git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/mctp/route.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"cc561f8af25586300c2f9d285babb163b866b293","status":"affected","version":"22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1","versionType":"git"},{"lessThan":"408da1df18116c971c3392e21e50586688cd3fbf","status":"affected","version":"22cb45afd221b9e4f2a1dcc74a8ff645b7293aa1","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/mctp/route.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mctp: hold a reference to the route device in mctp_route_lookup()\n\nmctp_route_lookup() uses rt->dev without holding a reference on it.\nmctp_route_lookup_single() returns the route under RCU only, so the\nroute's device can be torn down concurrently: mctp_dev_put() drops the\nlast reference and synchronously kfree()s mdev->addrs.  mctp_dev_saddr()\nthen reads rt->dev->addrs[0], giving a use-after-free reachable by an\nunprivileged local AF_MCTP user on the receive/forwarding path (no\nCAP_NET_RAW required):\n\n  BUG: KASAN: slab-use-after-free in mctp_route_lookup\n  Read of size 1 at addr ... by task mctp_uaf/...\n   mctp_route_lookup\n   mctp_pkttype_receive\n  Freed by task ...:\n   kfree\n   mctp_dev_put\n   mctp_dev_notify\n\nIn the same window mctp_dst_from_route() -> mctp_dev_hold() also\nincrements a refcount that has already reached zero\n(\"refcount_t: addition on 0 ... mctp_dev_hold\").\n\nThis reintroduces the use-after-free class of CVE-2023-3439: the source\naddress lookup was moved ahead of the point where the destination takes\nits device reference.\n\nTake a reference with refcount_inc_not_zero() before touching rt->dev,\nskip a device that is already dead, and drop the reference once the\ndestination has taken its own."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:42:50.866Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/cc561f8af25586300c2f9d285babb163b866b293"},{"url":"https://git.kernel.org/stable/c/408da1df18116c971c3392e21e50586688cd3fbf"}],"title":"net: mctp: hold a reference to the route device in mctp_route_lookup()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80995","datePublished":"2026-09-11T19:42:50.866Z","dateReserved":"2026-08-26T14:34:25.812Z","dateUpdated":"2026-09-11T19:42:50.866Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:06","lastModifiedDate":"2026-09-11 20:19:06","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80995","Ordinal":"1","Title":"net: mctp: hold a reference to the route device in mctp_route_lo","CVE":"CVE-2026-80995","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80995","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mctp: hold a reference to the route device in mctp_route_lookup()\n\nmctp_route_lookup() uses rt->dev without holding a reference on it.\nmctp_route_lookup_single() returns the route under RCU only, so the\nroute's device can be torn down concurrently: mctp_dev_put() drops the\nlast reference and synchronously kfree()s mdev->addrs.  mctp_dev_saddr()\nthen reads rt->dev->addrs[0], giving a use-after-free reachable by an\nunprivileged local AF_MCTP user on the receive/forwarding path (no\nCAP_NET_RAW required):\n\n  BUG: KASAN: slab-use-after-free in mctp_route_lookup\n  Read of size 1 at addr ... by task mctp_uaf/...\n   mctp_route_lookup\n   mctp_pkttype_receive\n  Freed by task ...:\n   kfree\n   mctp_dev_put\n   mctp_dev_notify\n\nIn the same window mctp_dst_from_route() -> mctp_dev_hold() also\nincrements a refcount that has already reached zero\n(\"refcount_t: addition on 0 ... mctp_dev_hold\").\n\nThis reintroduces the use-after-free class of CVE-2023-3439: the source\naddress lookup was moved ahead of the point where the destination takes\nits device reference.\n\nTake a reference with refcount_inc_not_zero() before touching rt->dev,\nskip a device that is already dead, and drop the reference once the\ndestination has taken its own.","Type":"Description","Title":"net: mctp: hold a reference to the route device in mctp_route_lo"}]}}}