CVE-2026-41893

HIGH

Signal K Server's WebSocket Login Endpoint Lacks Rate Limiting (Credential Brute-Force)

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 7.5
EPSS 0.0033
EPSS Percentile 24.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-307
Status published
Products (3)
npm/signalk-server 0 - 2.25.0npm
signalk/signal_k_server < 2.25.0
SignalK/signalk-server < 2.25.0
Published May 09, 2026
Tracked Since May 10, 2026