GHSA-H3C9-J2J5-6MFF

Vulnerability from github – Published: 2026-06-25 09:31 – Updated: 2026-06-28 09:31
VLAI
Details

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

ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()

In vti6_tnl_lookup(), when an exact match for a tunnel fails, the code falls back to searching for wildcard tunnels:

  • Tunnels matching the packet's local address, with any remote address wildcard remote).

  • Tunnels matching the packet's remote address, with any local address (wildcard local).

However, vti6 stores all these different types of tunnels in the same hash table (ip6n->tnls_r_l) prone to hash collisions.

The bug is that the fallback search loops in vti6_tnl_lookup() were missing checks to ensure that the candidate tunnel actually has a wildcard address.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-53221"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-25T09:16:39Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()\n\nIn vti6_tnl_lookup(), when an exact match for a tunnel fails,\nthe code falls back to searching for wildcard tunnels:\n\n- Tunnels matching the packet\u0027s local address, with any remote address\n  wildcard remote).\n\n- Tunnels matching the packet\u0027s remote address, with any local address\n  (wildcard local).\n\nHowever, vti6 stores all these different types of tunnels in the same\nhash table (ip6n-\u003etnls_r_l) prone to hash collisions.\n\nThe bug is that the fallback search loops in vti6_tnl_lookup() were\nmissing checks to ensure that the candidate tunnel actually has\na wildcard address.",
  "id": "GHSA-h3c9-j2j5-6mff",
  "modified": "2026-06-28T09:31:45Z",
  "published": "2026-06-25T09:31:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53221"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.