{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-97417", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-24T14:53:16.867Z", "datePublished": "2026-09-24T16:03:27.069Z", "dateUpdated": "2026-10-03T10:58:08.961Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-03T10:58:08.961Z" }, "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": { "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" }, "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_conntrack_proto_tcp.c" ], "versions": [ { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "740ad3d17a281f7764dda4dbeb37cea52e2e31ae", "status": "affected", "versionType": "git" }, { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "a0523267de2523522b0f70972dd1ffa22ec6176c", "status": "affected", "versionType": "git" }, { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "55bcc3376cd7b18954cc9814da697504fdaf12bf", "status": "affected", "versionType": "git" }, { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "0d5ad732e4fdc569eb85861115e8f7b4c2c67852", "status": "affected", "versionType": "git" }, { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "7ecfa46a536578a7ed335ddf31a854127268c27c", "status": "affected", "versionType": "git" }, { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "4abc1af7ac209c066f4e5dd75cdd56876e5829a9", "status": "affected", "versionType": "git" }, { "version": "bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9", "lessThan": "d3bf9eae486490832bd08fd62ab0ac601f346bd4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_conntrack_proto_tcp.c" ], "versions": [ { "version": "3.1", "status": "affected" }, { "version": "0", "lessThan": "3.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "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": "3.1", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/740ad3d17a281f7764dda4dbeb37cea52e2e31ae" }, { "url": "https://git.kernel.org/stable/c/a0523267de2523522b0f70972dd1ffa22ec6176c" }, { "url": "https://git.kernel.org/stable/c/55bcc3376cd7b18954cc9814da697504fdaf12bf" }, { "url": "https://git.kernel.org/stable/c/0d5ad732e4fdc569eb85861115e8f7b4c2c67852" }, { "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" } } } }