websocket-driver: Denial of service via malformed Host header
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-248.
Summary
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 it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| faye | websocket-driver-ruby | before 0.8.2 | 0.8.2 | Patch available | CNA |
| — | websocket-driver (RubyGems) | before 0.8.2 | 0.8.2 | Patch available | GHSA-2x63-gw47-w4mm |
- websocket-driver-ruby Vendorfaye Affected before 0.8.2 Fixed in 0.8.2 Patch available CNA
- websocket-driver (RubyGems) Vendor— Affected before 0.8.2 Fixed in 0.8.2 Patch available GHSA-2x63-gw47-w4mm
Remediation
- Fix · CNA websocket-driver-ruby (faye) Fixed in 0.8.2
- Fix · GHSA-2x63-gw47-w4mm websocket-driver (RubyGems) Fixed in 0.8.2 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Satellite 6 | Affected | — |
Not affected: 1 product
- Red Hat 3scale API Management Platform 2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-61666
- 2026-10-03 Alias added: GHSA-2x63-gw47-w4mm
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-09 Affected versions changed · Red Hat
- 2026-11-02 2 new references · GHSA-2x63-gw47-w4mm
References
Other 4
- https://github.com/faye/websocket-driver-ruby/security/advisories/GHSA-2x63-gw47-w4mm
- https://github.com/faye/websocket-driver-ruby/commit/7d6fd87759a2fdc83590d3b49ffa661dc53fa128
- https://github.com/faye/websocket-driver-ruby
- https://github.com/rubysec/ruby-advisory-db/blob/a58f1d0a3343e85cef597970f2c5458dcfbaf909/gems/websocket-driver/CVE-2026-61666.yml
More faye vulnerabilities
- TI-2026-39323 websocket-driver: Message corruption via abuse of protocol length headers CVSS 4.0CRITICAL 9.2
- TI-2020-08894 Authentication and extension bypass in Faye CVSS 3.1CRITICAL 9.8
- TI-2020-11907 Missing TLS certificate verification in Faye CVSS 3.1HIGH 8.7
- TI-2020-11906 Missing TLS certificate verification in Faye Websocket CVSS 3.1HIGH 8.7
- TI-2026-39320 websocket-driver: Memory exhaustion via abuse of protocol length headers CVSS 4.0MEDIUM 6.9
- TI-2026-39336 websocket-driver: Resource limit bypass via message compression CVSS 4.0MEDIUM 6.3
Sources
- CVE-2026-61666 · CVE Program
- CVE-2026-61666 · NVD
- FIRST EPSS
- GHSA-2x63-gw47-w4mm · GitHub Advisory Database · CC BY 4.0
- CVE-2026-61666 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences