{"api_version":"1","generated_at":"2026-10-26T07:26:28+00:00","cve":"CVE-2026-98525","urls":{"html":"https://cve.report/CVE-2026-98525","api":"https://cve.report/api/cve/CVE-2026-98525.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98525","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98525"},"summary":{"title":"mctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()\n\nWhen a socket transmits a packet with MCTP_TAG_PREALLOC set,\nmctp_lookup_prealloc_tag() iterates over the per-netns &mns->keys list\nand matches netid, req_tag, peer_addr, and manual_alloc, without\nchecking whether tmp->sk == &msk->sk. This allows any MCTP socket in the\nsame network namespace to use and consume another socket's preallocated\ntag.\n\nIterate the socket's own tag list (&msk->keys via sklist) instead of the\nnamespace-wide &mns->keys list in mctp_lookup_prealloc_tag(), ensuring\nthat only tags allocated by msk are matched.\n\nTested in QEMU against Linux 7.3.0-rc3 by allocating a manual tag\n(0x18) on socket A via SIOCMCTPALLOCTAG for peer EID 9 and sending a\n4-byte message with MCTP_TAG_PREALLOC from socket B in the same network\nnamespace. On the unfixed kernel, sendto(sock_b) using socket A's\npreallocated tag succeeds (ret = 4); with this patch applied,\nsendto(sock_b) fails with -ENOENT (errno = 2) while sendto(sock_a)\nsucceeds (ret = 4).","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:03","updated_at":"2026-10-18 16:17:03"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/e35cb500dd14882f8dee61783fccd1823fd3ab0d","name":"https://git.kernel.org/stable/c/e35cb500dd14882f8dee61783fccd1823fd3ab0d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/26cc0e69cce062cd3aa6fae33074684669c35a71","name":"https://git.kernel.org/stable/c/26cc0e69cce062cd3aa6fae33074684669c35a71","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/09299addab11857e92eca55cd8ef3350b927c90c","name":"https://git.kernel.org/stable/c/09299addab11857e92eca55cd8ef3350b927c90c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f178300e2f56ca9ec2a3a0090608730bbee0af7b","name":"https://git.kernel.org/stable/c/f178300e2f56ca9ec2a3a0090608730bbee0af7b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98525","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98525","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 63ed1aab3d40aa61aaa66819bdce9377ac7f40fa 09299addab11857e92eca55cd8ef3350b927c90c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 63ed1aab3d40aa61aaa66819bdce9377ac7f40fa e35cb500dd14882f8dee61783fccd1823fd3ab0d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 63ed1aab3d40aa61aaa66819bdce9377ac7f40fa f178300e2f56ca9ec2a3a0090608730bbee0af7b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 63ed1aab3d40aa61aaa66819bdce9377ac7f40fa 26cc0e69cce062cd3aa6fae33074684669c35a71 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.18","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.112 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.55 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.9 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * 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":"09299addab11857e92eca55cd8ef3350b927c90c","status":"affected","version":"63ed1aab3d40aa61aaa66819bdce9377ac7f40fa","versionType":"git"},{"lessThan":"e35cb500dd14882f8dee61783fccd1823fd3ab0d","status":"affected","version":"63ed1aab3d40aa61aaa66819bdce9377ac7f40fa","versionType":"git"},{"lessThan":"f178300e2f56ca9ec2a3a0090608730bbee0af7b","status":"affected","version":"63ed1aab3d40aa61aaa66819bdce9377ac7f40fa","versionType":"git"},{"lessThan":"26cc0e69cce062cd3aa6fae33074684669c35a71","status":"affected","version":"63ed1aab3d40aa61aaa66819bdce9377ac7f40fa","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":"5.18"},{"lessThan":"5.18","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.112","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.55","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.112","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.55","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.9","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"5.18","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()\n\nWhen a socket transmits a packet with MCTP_TAG_PREALLOC set,\nmctp_lookup_prealloc_tag() iterates over the per-netns &mns->keys list\nand matches netid, req_tag, peer_addr, and manual_alloc, without\nchecking whether tmp->sk == &msk->sk. This allows any MCTP socket in the\nsame network namespace to use and consume another socket's preallocated\ntag.\n\nIterate the socket's own tag list (&msk->keys via sklist) instead of the\nnamespace-wide &mns->keys list in mctp_lookup_prealloc_tag(), ensuring\nthat only tags allocated by msk are matched.\n\nTested in QEMU against Linux 7.3.0-rc3 by allocating a manual tag\n(0x18) on socket A via SIOCMCTPALLOCTAG for peer EID 9 and sending a\n4-byte message with MCTP_TAG_PREALLOC from socket B in the same network\nnamespace. On the unfixed kernel, sendto(sock_b) using socket A's\npreallocated tag succeeds (ret = 4); with this patch applied,\nsendto(sock_b) fails with -ENOENT (errno = 2) while sendto(sock_a)\nsucceeds (ret = 4)."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:21:07.010Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/09299addab11857e92eca55cd8ef3350b927c90c"},{"url":"https://git.kernel.org/stable/c/e35cb500dd14882f8dee61783fccd1823fd3ab0d"},{"url":"https://git.kernel.org/stable/c/f178300e2f56ca9ec2a3a0090608730bbee0af7b"},{"url":"https://git.kernel.org/stable/c/26cc0e69cce062cd3aa6fae33074684669c35a71"}],"title":"mctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98525","datePublished":"2026-10-18T15:17:43.216Z","dateReserved":"2026-09-25T10:25:14.355Z","dateUpdated":"2026-10-19T09:21:07.010Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:03","lastModifiedDate":"2026-10-18 16:17:03","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98525","Ordinal":"1","Title":"mctp: route: iterate socket tag list in mctp_lookup_prealloc_tag","CVE":"CVE-2026-98525","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98525","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmctp: route: iterate socket tag list in mctp_lookup_prealloc_tag()\n\nWhen a socket transmits a packet with MCTP_TAG_PREALLOC set,\nmctp_lookup_prealloc_tag() iterates over the per-netns &mns->keys list\nand matches netid, req_tag, peer_addr, and manual_alloc, without\nchecking whether tmp->sk == &msk->sk. This allows any MCTP socket in the\nsame network namespace to use and consume another socket's preallocated\ntag.\n\nIterate the socket's own tag list (&msk->keys via sklist) instead of the\nnamespace-wide &mns->keys list in mctp_lookup_prealloc_tag(), ensuring\nthat only tags allocated by msk are matched.\n\nTested in QEMU against Linux 7.3.0-rc3 by allocating a manual tag\n(0x18) on socket A via SIOCMCTPALLOCTAG for peer EID 9 and sending a\n4-byte message with MCTP_TAG_PREALLOC from socket B in the same network\nnamespace. On the unfixed kernel, sendto(sock_b) using socket A's\npreallocated tag succeeds (ret = 4); with this patch applied,\nsendto(sock_b) fails with -ENOENT (errno = 2) while sendto(sock_a)\nsucceeds (ret = 4).","Type":"Description","Title":"mctp: route: iterate socket tag list in mctp_lookup_prealloc_tag"}]}}}