PatchTheCVECVE-2026-61666: websocket-driver is a WebSocket protocol handler with pluggable I/O
CVE-2026-61666 is a high-severity flaw (CVSS 8.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.2, WebSocket::Driver.server() passes a malformed Host header to URI.parse in lib/websocket/http/request.rb without catching URI::InvalidURIError, allowing a remote client to crash a TCP-backed WebSocket server when the application does not catch the error from parse(). This issue is fixed in version 0.8.2.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.9 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 62%) |
| CISA exploited list | No |
| Weakness | CWE-248 |
| Published | 2026-08-17 |
| Last modified | 2026-10-23 |
Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-61666?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-61666 being exploited?
CVE-2026-61666 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-61666 affect?
CVE-2026-61666 affects affected software. Severity is high (CVSS 8.9). websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.2, WebSocket::Driver.server() passes a malformed Host header to URI.parse in lib/websocket/http/request.rb without catching URI::InvalidURIError, allowing a r
How urgent is CVE-2026-61666?
Priority 46/100. High severity; Remotely exploitable, no login, no user action