Vulnerability-Lookup

GHSA-XC67-X6QC-F6HF

Vulnerability from github – Published: 2026-08-28 09:31 – Updated: 2026-08-28 09:31

Details

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

netfilter: conntrack: revert ct extension genid infrastructure

This infrastructure is not used anymore after moving ct timeout and helper to use datapath refcount to track object use.

Revert commit c56716c69ce1 ("netfilter: extensions: introduce extension genid count") this patch disables all ct extensions (leading to NULL) for unconfirmed conntracks, when this is only targeted at ct helper and ct timeout. There is also codebase that dereferences the ct extension without checking for NULL which could lead to crash.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-80636"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-28T08:16:48Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: revert ct extension genid infrastructure\n\nThis infrastructure is not used anymore after moving ct timeout and\nhelper to use datapath refcount to track object use.\n\nRevert commit c56716c69ce1 (\"netfilter: extensions: introduce extension\ngenid count\") this patch disables all ct extensions (leading to NULL)\nfor unconfirmed conntracks, when this is only targeted at ct helper and\nct timeout. There is also codebase that dereferences the ct extension\nwithout checking for NULL which could lead to crash.",
  "id": "GHSA-xc67-x6qc-f6hf",
  "modified": "2026-08-28T09:31:47Z",
  "published": "2026-08-28T09:31:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80636"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/35e21a4dccc5c255ba59ccfbfeb4629ed21da972"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/61eab1d0237eb513fe73e391a5926ee70092c325"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6bba4846f196d081bf553391d12b5a73dcc48685"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a052a94bcc629acaecc2ce42a4af77f8fa399757"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d53eecbca16f056abba274075cb15120ab062518"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-80636 (GCVE-0-2026-80636)

Vulnerability from cvelistv5 – Published: 2026-08-28 06:48 – Updated: 2026-08-28 06:48

Title

netfilter: conntrack: revert ct extension genid infrastructure

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: revert ct extension genid infrastructure This infrastructure is not used anymore after moving ct timeout and helper to use datapath refcount to track object use. Revert commit c56716c69ce1 ("netfilter: extensions: introduce extension genid count") this patch disables all ct extensions (leading to NULL) for unconfirmed conntracks, when this is only targeted at ct helper and ct timeout. There is also codebase that dereferences the ct extension without checking for NULL which could lead to crash.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/6bba4846f196d081b…
https://git.kernel.org/stable/c/61eab1d0237eb513f…
https://git.kernel.org/stable/c/d53eecbca16f056ab…
https://git.kernel.org/stable/c/a052a94bcc629acae…
https://git.kernel.org/stable/c/35e21a4dccc5c255b…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c56716c69ce1ac320432fb1ea5654196ba24d2f8 , < 6bba4846f196d081bf553391d12b5a73dcc48685 (git) Affected: c56716c69ce1ac320432fb1ea5654196ba24d2f8 , < 61eab1d0237eb513fe73e391a5926ee70092c325 (git) Affected: c56716c69ce1ac320432fb1ea5654196ba24d2f8 , < d53eecbca16f056abba274075cb15120ab062518 (git) Affected: c56716c69ce1ac320432fb1ea5654196ba24d2f8 , < a052a94bcc629acaecc2ce42a4af77f8fa399757 (git) Affected: c56716c69ce1ac320432fb1ea5654196ba24d2f8 , < 35e21a4dccc5c255ba59ccfbfeb4629ed21da972 (git)
Linux	Linux	Affected: 5.19 Unaffected: 0 , < 5.19 (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
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        {
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          "programFiles": [
            "include/net/netfilter/nf_conntrack_extend.h",
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          "versions": [
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              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
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        }
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: revert ct extension genid infrastructure\n\nThis infrastructure is not used anymore after moving ct timeout and\nhelper to use datapath refcount to track object use.\n\nRevert commit c56716c69ce1 (\"netfilter: extensions: introduce extension\ngenid count\") this patch disables all ct extensions (leading to NULL)\nfor unconfirmed conntracks, when this is only targeted at ct helper and\nct timeout. There is also codebase that dereferences the ct extension\nwithout checking for NULL which could lead to crash."
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    "datePublished": "2026-08-28T06:48:50.241Z",
    "dateReserved": "2026-08-26T14:34:25.777Z",
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}

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.

Detection rules are retrieved from Rulezet.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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