Vulnerability-Lookup

GHSA-86RV-J9HX-PV73

Vulnerability from github – Published: 2026-09-24 18:31 – Updated: 2026-09-25 06:30

Details

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()

The timestamp-only fast path dereferences the option stream as (__be32 )ptr, which assumes 4-byte alignment that the TCP option stream does not guarantee. Use get_unaligned_be32() instead, which reads the value safely and already returns host byte order, so the htonl() on the comparison constant can be dropped.

This matches the existing get_unaligned_be32() use later in the same function.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-97417"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-24T17:17:19Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-86rv-j9hx-pv73",
  "modified": "2026-09-25T06:30:31Z",
  "published": "2026-09-24T18:31:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97417"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4abc1af7ac209c066f4e5dd75cdd56876e5829a9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7ecfa46a536578a7ed335ddf31a854127268c27c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d3bf9eae486490832bd08fd62ab0ac601f346bd4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-97417 (GCVE-0-2026-97417)

Vulnerability from cvelistv5 – Published: 2026-09-24 16:03 – Updated: 2026-09-25 12:43

Title

netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack() The timestamp-only fast path dereferences the option stream as *(__be32 *)ptr, which assumes 4-byte alignment that the TCP option stream does not guarantee. Use get_unaligned_be32() instead, which reads the value safely and already returns host byte order, so the htonl() on the comparison constant can be dropped. This matches the existing get_unaligned_be32() use later in the same function.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/7ecfa46a536578a7e…
https://git.kernel.org/stable/c/4abc1af7ac209c066…
https://git.kernel.org/stable/c/d3bf9eae486490832…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9 , < 7ecfa46a536578a7ed335ddf31a854127268c27c (git) Affected: bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9 , < 4abc1af7ac209c066f4e5dd75cdd56876e5829a9 (git) Affected: bb9fc37358ffa9de1cc2b2b6f1a559b926ef50d9 , < d3bf9eae486490832bd08fd62ab0ac601f346bd4 (git)
Linux	Linux	Affected: 3.1 Unaffected: 0 , < 3.1 (semver) Unaffected: 6.12.111 , ≤ 6.12.* (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "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()\u2192nf_conntrack_tcp_packet()\u2192tcp_in_window()\u2192tcp_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()\u0027s 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\u0027s 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\u0027s 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()\u0027s 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"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-86RV-J9HX-PV73

CVE-2026-97417 (GCVE-0-2026-97417)

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