GHSA-6W86-WGWQ-RGQ8

Vulnerability from github – Published: 2026-03-04 20:16 – Updated: 2026-03-04 20:16
VLAI
Summary
neqo-qpack has iInteger overflow in qpack dynamic table indexing
Details

Summary

An unsanitized qpack index can lead to an integer overflow, panicing in debug mode, accessing the wrong or no dynamic table entry in release mode.

What does this mean for Firefox? Firefox runs Neqo in release mode. A malicious remote can cause its own QUIC connection to fail to use qpack, i.e. compression, or enter an inconsistent state. The remote can not crash Firefox, nor affect other QUIC connections.

Details

See fuzz report in https://github.com/mozilla/neqo/issues/3406.

PoC

See test in pull request.

Impact

All Firefox users. Though vulnerability likely scoped to same connection, i.e. low impact.

Severity
5.1 (Medium)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "neqo-qpack"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.22.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-04T20:16:26Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nAn unsanitized qpack index can lead to an integer overflow, panicing in debug mode, accessing the wrong or no dynamic table entry in release mode.\n\nWhat does this mean for Firefox? Firefox runs Neqo in release mode. A malicious remote can cause its own QUIC connection to fail to use qpack, i.e. compression, or enter an inconsistent state. The remote can not crash Firefox, nor affect other QUIC connections. \n\n### Details\n\nSee fuzz report in https://github.com/mozilla/neqo/issues/3406.\n\n### PoC\nSee test in pull request.\n\n### Impact\nAll Firefox users. Though vulnerability likely scoped to same connection, i.e. low impact.",
  "id": "GHSA-6w86-wgwq-rgq8",
  "modified": "2026-03-04T20:16:26Z",
  "published": "2026-03-04T20:16:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mozilla/neqo/security/advisories/GHSA-6w86-wgwq-rgq8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mozilla/neqo/issues/3406"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mozilla/neqo"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "neqo-qpack has iInteger overflow in qpack dynamic table indexing"
}



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