{"id":"CVE-2026-31407","state":"PUBLISHED","title":"netfilter: conntrack: add missing netlink policy validations","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: add missing netlink policy validations\n\nHyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.\n\nThese attributes are used by the kernel without any validation.\nExtend the netlink policies accordingly.\n\nQuoting the reporter:\n  nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE\n  value directly to ct->proto.sctp.state without checking that it is\n  within the valid range. [..]\n\n  and: ... with exp->dir = 100, the access at\n  ct->master->tuplehash[100] reads 5600 bytes past the start of a\n  320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by\n  UBSAN.","publishedAt":"2026-04-06T07:38:19.712Z","updatedAt":"2026-10-19T18:35:47.097Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"e7b5766693477c52424cc6c79dd30a7a9c7db52c","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"78bba9f73942aa7dca47d817d8cec0fb9b443b70","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"be88a337bf07afb1ee173f1099294d1b7ab3fefe","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"c5e918390002edf0cff80a0e7ce1f86f16a9507c","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"9174d28f3f15d8c4962f5980c0be167633880443","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"67c53c1978cef3c504237275e39c857e2f6af56e","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"0fbae1e74493d5a160a70c51aeba035d8266ea7d","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_proto_sctp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.27","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.27","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.83","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.24","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.10","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_proto_sctp.c"]}],"references":["https://git.kernel.org/stable/c/e7b5766693477c52424cc6c79dd30a7a9c7db52c","https://git.kernel.org/stable/c/78bba9f73942aa7dca47d817d8cec0fb9b443b70","https://git.kernel.org/stable/c/be88a337bf07afb1ee173f1099294d1b7ab3fefe","https://git.kernel.org/stable/c/c5e918390002edf0cff80a0e7ce1f86f16a9507c","https://git.kernel.org/stable/c/9174d28f3f15d8c4962f5980c0be167633880443","https://git.kernel.org/stable/c/67c53c1978cef3c504237275e39c857e2f6af56e","https://git.kernel.org/stable/c/0fbae1e74493d5a160a70c51aeba035d8266ea7d","https://git.kernel.org/stable/c/f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31407.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31407","state":"PUBLISHED","datePublished":"2026-04-06T07:38:19.712Z","dateUpdated":"2026-10-19T18:35:47.097Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.086Z"},"containers":{"cna":{"title":"netfilter: conntrack: add missing netlink policy validations","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: add missing netlink policy validations\n\nHyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.\n\nThese attributes are used by the kernel without any validation.\nExtend the netlink policies accordingly.\n\nQuoting the reporter:\n  nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE\n  value directly to ct->proto.sctp.state without checking that it is\n  within the valid range. [..]\n\n  and: ... with exp->dir = 100, the access at\n  ct->master->tuplehash[100] reads 5600 bytes past the start of a\n  320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by\n  UBSAN."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"e7b5766693477c52424cc6c79dd30a7a9c7db52c","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"78bba9f73942aa7dca47d817d8cec0fb9b443b70","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"be88a337bf07afb1ee173f1099294d1b7ab3fefe","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"c5e918390002edf0cff80a0e7ce1f86f16a9507c","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"9174d28f3f15d8c4962f5980c0be167633880443","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"67c53c1978cef3c504237275e39c857e2f6af56e","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"0fbae1e74493d5a160a70c51aeba035d8266ea7d","versionType":"git"},{"version":"a258860e01b80e8f554a4ab1a6c95e6042eb8b73","status":"affected","lessThan":"f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_proto_sctp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.27","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.27","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.136","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.83","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.24","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.10","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_proto_sctp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e7b5766693477c52424cc6c79dd30a7a9c7db52c"},{"url":"https://git.kernel.org/stable/c/78bba9f73942aa7dca47d817d8cec0fb9b443b70"},{"url":"https://git.kernel.org/stable/c/be88a337bf07afb1ee173f1099294d1b7ab3fefe"},{"url":"https://git.kernel.org/stable/c/c5e918390002edf0cff80a0e7ce1f86f16a9507c"},{"url":"https://git.kernel.org/stable/c/9174d28f3f15d8c4962f5980c0be167633880443"},{"url":"https://git.kernel.org/stable/c/67c53c1978cef3c504237275e39c857e2f6af56e"},{"url":"https://git.kernel.org/stable/c/0fbae1e74493d5a160a70c51aeba035d8266ea7d"},{"url":"https://git.kernel.org/stable/c/f900e1d77ee0ef87bfb5ab3fe60f0b3d8ad5ba05"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Reachability is through NETLINK_NETFILTER ctnetlink messages sent by a local process. Later packet processing can trigger the bad state or expectation, but the attacker must first inject the malformed conntrack/expectation attributes locally.\nAC:L - The bug is triggered with crafted netlink attributes and does not require winning a race. The attacker can create the relevant conntrack/expectation state and matching traffic in a controlled network namespace.\nPR:L - nfnetlink requires CAP_NET_ADMIN in the socket's network namespace. Because this capability is reachable via user and network namespaces on affected deployments, this is low privilege rather than high privilege.\nUI:N - No victim action is required after the attacker can send the netlink request. The attacker can trigger the vulnerable paths directly.\nS:U - The impact remains within the kernel security authority. This is not a VM escape or cross-authority boundary bypass.\nC:H - The missing validation permits attacker-controlled out-of-bounds reads, including indexing beyond the master nf_conn tuplehash and SCTP state tables. This is not strictly bounded to a harmless few bytes, so high confidentiality impact is defensible.\nI:N - The investigated paths show out-of-bounds reads and invalid in-object state assignment, not an out-of-bounds write or control-flow overwrite. No direct integrity-impacting primitive was identified.\nA:H - The out-of-bounds reads are attacker-triggerable and were reported as UBSAN-confirmed slab out-of-bounds accesses. Such kernel faults can produce an oops or panic, so availability impact is high."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:22:16.533Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.6.136"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.12.83"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.18.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.19.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:15:46.395Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-31407","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:08:59.610705Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:35:47.097Z"}}]}}}