GHSA-2X63-GW47-W4MM

Vulnerability from github – Published: 2026-07-21 18:34 – Updated: 2026-07-21 18:34
VLAI
Summary
websocket-driver-ruby: Denial of service via malformed Host header
Details

Impact

If this library is used to implement a WebSocket server on top of a TCP server, by using the WebSocket::Driver.server() method, then a client can cause the server to crash by sending a Host header that is not a valid host[:port] string. When this happens, a URI::InvalidURIError exception is raised which is not caught, and this can cause the server process to crash if the application does not catch the error from the parse() method itself.

Patches

The issue has been patched in version 0.8.2 by making the request parser catch URI::InvalidURIError and enter an error state if the Host header is malformed. This means the request is considered invalid and should not establish a WebSocket connection.

Workarounds

No known workarounds exist.

Acknowledgements

This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.

Severity
8.9 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "websocket-driver"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.8.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-61666"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-248"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-21T18:34:42Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nIf this library is used to implement a WebSocket server on top of a TCP server, by using the `WebSocket::Driver.server()` method, then a client can cause the server to crash by sending a `Host` header that is not a valid `host[:port]` string. When this happens, a `URI::InvalidURIError` exception is raised which is not caught, and this can cause the server process to crash if the application does not catch the error from the `parse()` method itself.\n\n### Patches\n\nThe issue has been patched in version 0.8.2 by making the request parser catch `URI::InvalidURIError` and enter an error state if the `Host` header is malformed. This means the request is considered invalid and should not establish a WebSocket connection.\n\n### Workarounds\n\nNo known workarounds exist.\n\n### Acknowledgements\n\nThis issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.",
  "id": "GHSA-2x63-gw47-w4mm",
  "modified": "2026-07-21T18:34:42Z",
  "published": "2026-07-21T18:34:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/faye/websocket-driver-ruby/security/advisories/GHSA-2x63-gw47-w4mm"
    },
    {
      "type": "WEB",
      "url": "https://github.com/faye/websocket-driver-ruby/commit/7d6fd87759a2fdc83590d3b49ffa661dc53fa128"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/faye/websocket-driver-ruby"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "websocket-driver-ruby: Denial of service via malformed Host header"
}



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