Vulnerability details
CVE-2026-41893
Signal K Server's WebSocket Login Endpoint Lacks Rate Limiting (Credential Brute-Force)
Official description
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.7High | 4.0 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| SignalK | signalk-server | < 2.25.0 | CVEProject cvelistV5 (CNA) |
References and advisories
4- https://github.com/SignalK/signalk-server/pull/2568 x_refsource_MISC
- https://github.com/SignalK/signalk-server/commit/215d81eb700d5419c3396a0fbf23f2e246dfac2d x_refsource_MISC
- https://github.com/SignalK/signalk-server/releases/tag/v2.25.0 x_refsource_MISC
- https://github.com/SignalK/signalk-server/security/advisories/GHSA-vmfm-ch9h-5c7g x_refsource_CONFIRM
Details
- Published
- 2026-05-09
- Last updated
- 2026-05-14
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- Proof of concept
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-307Improper Restriction of Excessive Authentication Attempts