CVE-2026-41893
Signal K Server's WebSocket Login Endpoint Lacks Rate Limiting (Credential Brute-Force)
Impact
Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.25.0, the HTTP login endpoints (POST /login and POST /signalk/v1/auth/login) are protected by express-rate-limit (default: 100 attempts per 10-minute window, configurable via HTTP_RATE_LIMITS). The WebSocket login path — sending {login: {username, password}} messages over an established WebSocket connection — calls app.securityStrategy.login() directly without any rate limiting. An attacker can bypass HTTP rate limiting entirely by opening a WebSocket connection and attempting unlimited password guesses at the speed bcrypt allows (~20 attempts/sec with 10 salt rounds). This issue has been patched in version 2.25.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | signalk-server | <= 2.24.0 | 2.25.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Signalk | Signal K Server | before 2.25.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-vmfm-ch9h-5c7g
- https://github.com/SignalK/signalk-server/security/advisories/GHSA-vmfm-ch9h-5c7g
- https://nvd.nist.gov/vuln/detail/CVE-2026-41893
- https://github.com/SignalK/signalk-server/pull/2568
- https://github.com/SignalK/signalk-server/commit/215d81eb700d5419c3396a0fbf23f2e246dfac2d
- https://github.com/SignalK/signalk-server/releases/tag/v2.25.0