GitHub Advisoryadvisory · RubyGems

GHSA-2x63-gw47-w4mm websocket-driver-ruby: Denial of service via malformed Host header

HIGH Published 2026-07-21 Modified 2026-11-02 Official page ↗
Aliases
CVE-2026-61666
Ecosystem
RubyGems
Packages
websocket-driver
Severity
High
CVSS vector
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
Weaknesses
CWE-248
Reviewed
2026-07-21

Affected packages

• RubyGems websocket-driver: < 0.8.2 → fixed in 0.8.2

Description

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.

Related

Alias · CVE (1)

  • CVE-2026-61666 websocket-driver is a WebSocket protocol handler with pluggable I/O. vulnerability

Weakness · CWE (1)

  • CWE-248 Uncaught Exception weakness

References