websocket-driver-ruby: Denial of service via malformed Host header (CVE-2026-61666)
A denial of service vulnerability exists in the websocket-driver Ruby library when used to implement a WebSocket server. A client can send a malformed Host header that triggers an uncaught URI::InvalidURIError exception, potentially crashing the server process. This issue is fixed in version 0.8.2 by catching the exception and treating the request as invalid, preventing the crash. No workarounds are known.
AI Analysis
Technical Summary
The websocket-driver Ruby library prior to version 0.8.2 has a vulnerability where a malformed Host header in a WebSocket handshake request causes an uncaught URI::InvalidURIError exception. When using WebSocket::Driver.server(), this exception can crash the server process if the application does not handle the error from the parse() method. The vulnerability is addressed in version 0.8.2 by catching the exception and entering an error state, thus rejecting invalid requests and preventing denial of service.
Potential Impact
An attacker can cause a denial of service by crashing the WebSocket server process through sending a malformed Host header. This leads to server downtime or disruption of service until the process is restarted. The vulnerability requires no privileges and no user interaction, making it remotely exploitable over the network.
Mitigation Recommendations
Upgrade websocket-driver to version 0.8.2 or later, where the issue is patched by proper exception handling of malformed Host headers. No known workarounds exist. Applications should ensure they handle exceptions from the parse() method if using affected versions.
websocket-driver-ruby: Denial of service via malformed Host header (CVE-2026-61666)
Description
A denial of service vulnerability exists in the websocket-driver Ruby library when used to implement a WebSocket server. A client can send a malformed Host header that triggers an uncaught URI::InvalidURIError exception, potentially crashing the server process. This issue is fixed in version 0.8.2 by catching the exception and treating the request as invalid, preventing the crash. No workarounds are known.
CVSS v4.0
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The websocket-driver Ruby library prior to version 0.8.2 has a vulnerability where a malformed Host header in a WebSocket handshake request causes an uncaught URI::InvalidURIError exception. When using WebSocket::Driver.server(), this exception can crash the server process if the application does not handle the error from the parse() method. The vulnerability is addressed in version 0.8.2 by catching the exception and entering an error state, thus rejecting invalid requests and preventing denial of service.
Potential Impact
An attacker can cause a denial of service by crashing the WebSocket server process through sending a malformed Host header. This leads to server downtime or disruption of service until the process is restarted. The vulnerability requires no privileges and no user interaction, making it remotely exploitable over the network.
Mitigation Recommendations
Upgrade websocket-driver to version 0.8.2 or later, where the issue is patched by proper exception handling of malformed Host headers. No known workarounds exist. Applications should ensure they handle exceptions from the parse() method if using affected versions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-2x63-gw47-w4mm
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-61666"]
- Ecosystems
- ["RubyGems"]
- Database Specific Severity
- HIGH
- Cvss Version
- 4.0
Threat ID: 6a5fcf3c1010f89cc2151297
Added to database: 07/21/2026, 19:57:48 UTC
Last enriched: 07/21/2026, 20:35:44 UTC
Last updated: 07/21/2026, 20:35:44 UTC
Views: 2
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