{"api_version":"1","generated_at":"2026-10-01T09:04:11+00:00","cve":"CVE-2026-97417","urls":{"html":"https://cve.report/CVE-2026-97417","api":"https://cve.report/api/cve/CVE-2026-97417.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97417","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97417"},"summary":{"title":"netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()\n\nThe timestamp-only fast path dereferences the option stream as\n*(__be32 *)ptr, which assumes 4-byte alignment that the TCP option\nstream does not guarantee. Use get_unaligned_be32() instead, which\nreads the value safely and already returns host byte order, so the\nhtonl() on the comparison constant can be dropped.\n\nThis matches the existing get_unaligned_be32() use later in the same\nfunction.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-24 17:17:19","updated_at":"2026-09-25 13:17:25"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/4abc1af7ac209c066f4e5dd75cdd56876e5829a9","name":"https://git.kernel.org/stable/c/4abc1af7ac209c066f4e5dd75cdd56876e5829a9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d3bf9eae486490832bd08fd62ab0ac601f346bd4","name":"https://git.kernel.org/stable/c/d3bf9eae486490832bd08fd62ab0ac601f346bd4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7ecfa46a536578a7ed335ddf31a854127268c27c","name":"https://git.kernel.org/stable/c/7ecfa46a536578a7ed335ddf31a854127268c27c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97417","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97417","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9 7ecfa46a536578a7ed335ddf31a854127268c27c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9 4abc1af7ac209c066f4e5dd75cdd56876e5829a9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9 d3bf9eae486490832bd08fd62ab0ac601f346bd4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"97417","cve":"CVE-2026-97417","epss":"0.004260000","percentile":"0.343780000","score_date":"2026-09-27","updated_at":"2026-09-28 00:02:24"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/netfilter/nf_conntrack_proto_tcp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"7ecfa46a536578a7ed335ddf31a854127268c27c","status":"affected","version":"bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9","versionType":"git"},{"lessThan":"4abc1af7ac209c066f4e5dd75cdd56876e5829a9","status":"affected","version":"bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9","versionType":"git"},{"lessThan":"d3bf9eae486490832bd08fd62ab0ac601f346bd4","status":"affected","version":"bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/netfilter/nf_conntrack_proto_tcp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.1"},{"lessThan":"3.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"3.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"3.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"3.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()\n\nThe timestamp-only fast path dereferences the option stream as\n*(__be32 *)ptr, which assumes 4-byte alignment that the TCP option\nstream does not guarantee. Use get_unaligned_be32() instead, which\nreads the value safely and already returns host byte order, so the\nhtonl() on the comparison constant can be dropped.\n\nThis matches the existing get_unaligned_be32() use later in the same\nfunction."}],"metrics":[{"cvssV3_1":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - ipv4_conntrack_in() on NF_INET_PRE_ROUTING calls nf_conntrack_in()→nf_conntrack_tcp_packet()→tcp_in_window()→tcp_sack(); the *(__be32 *)ptr load reads the first four option bytes of a received TCP segment (doff=8, 12-byte NOP-NOP-TIMESTAMP block) that the remote peer put on the wire.\nAC:L - Default tcp_loose=1 makes tcp_new() set IP_CT_TCP_FLAG_SACK_PERM on both directions for a non-SYN ACK, so one attacker TCP ACK with doff=8 (length==TCPOLEN_TSTAMP_ALIGNED) reaches tcp_sack()'s timestamp fast path; on strict-alignment NAT/PPPoE paths where those options are 2-mod-4, *(__be32 *)ptr faults with no race.\nPR:N - ipv4_conntrack_in()/ipv6_conntrack_in() run in NF_INET_PRE_ROUTING; tcp_error() only checks header length, flags, and checksum before nf_conntrack_tcp_packet() reaches tcp_sack(), with no socket, credentials, or TCP-handshake authentication.\nUI:N - The PRE_ROUTING conntrack hook invokes tcp_sack() from softirq on the attacker's own TCP segment; no victim must mount media, open a file, or take any other interactive action.\nS:U - An alignment fault in tcp_sack() oopses the same host kernel that is conntracking the TCP flow; it does not cross a VM, guest-to-host, IOMMU, or other security authority.\nC:N - The timestamp fast path loads four in-bounds bytes of the packet's own TCP option stream after skb_header_pointer(..., length==12, ...); it is not an OOB or UAF read, and a strict-alignment fault discloses nothing beyond those attacker-supplied bytes.\nI:N - tcp_sack()'s defect is a read-only *(__be32 *)ptr of the option bytes; it does not write conntrack state or adjacent objects, and the fix only replaces that load with get_unaligned_be32().\nA:H - On SPARC, MIPS, and pre-v6 ARM (typical OpenWrt/CPE NAT boxes), the misaligned __be32 load in tcp_sack() raises a kernel alignment exception/oops/panic in netfilter softirq, fully denying host availability and repeatable by resending the segment."}]}],"providerMetadata":{"dateUpdated":"2026-09-25T12:43:52.382Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/7ecfa46a536578a7ed335ddf31a854127268c27c"},{"url":"https://git.kernel.org/stable/c/4abc1af7ac209c066f4e5dd75cdd56876e5829a9"},{"url":"https://git.kernel.org/stable/c/d3bf9eae486490832bd08fd62ab0ac601f346bd4"}],"title":"netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-97417","datePublished":"2026-09-24T16:03:27.069Z","dateReserved":"2026-09-24T14:53:16.867Z","dateUpdated":"2026-09-25T12:43:52.382Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-24 17:17:19","lastModifiedDate":"2026-09-25 13:17:25","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"97417","Ordinal":"1","Title":"netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()","CVE":"CVE-2026-97417","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"97417","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()\n\nThe timestamp-only fast path dereferences the option stream as\n*(__be32 *)ptr, which assumes 4-byte alignment that the TCP option\nstream does not guarantee. Use get_unaligned_be32() instead, which\nreads the value safely and already returns host byte order, so the\nhtonl() on the comparison constant can be dropped.\n\nThis matches the existing get_unaligned_be32() use later in the same\nfunction.","Type":"Description","Title":"netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()"}]}}}