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TI-2026-30295 Aliases CVE-2026-41893GHSA-vmfm-ch9h-5c7g

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

Priority HIGH 77CWE-307Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-307.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00327 25th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed signalk-server (SignalK): 2.25.0signalk-server (npm): 2.25.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
SignalKsignalk-serverbefore 2.25.02.25.0Patch availableCNA
—signalk-server (npm)before 2.25.02.25.0Patch availableGHSA-vmfm-ch9h-5c7g
  • signalk-server VendorSignalK Affected before 2.25.0 Fixed in 2.25.0 Patch available CNA
  • signalk-server (npm) Vendor— Affected before 2.25.0 Fixed in 2.25.0 Patch available GHSA-vmfm-ch9h-5c7g

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:signalk:signal_k_server:*:*:*:*:*:*:*:*before 2.25.0VulnerableSignalK
  • cpe:2.3:a:signalk:signal_k_server:*:*:*:*:*:*:*:* Versions before 2.25.0 Vulnerable ·SignalK

Remediation

  • Fix · CNA signalk-server (SignalK) Fixed in 2.25.0
  • Fix · GHSA-vmfm-ch9h-5c7g signalk-server (npm) Fixed in 2.25.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-41893
  2. 2026-10-03 Alias added: GHSA-vmfm-ch9h-5c7g

References

Exploit 1

Patch 2

Advisory 1

Other 2

  • TI-2026-26300 signalk-server: Privilege Escalation by Admin Role Injection via /enableSecurity CVSS 3.1CRITICAL 9.4
  • TI-2025-40835 Signal K Server has Unauthenticated State Pollution leading to Remote Code Execution (RCE) CVSS 3.1CRITICAL 9.7
  • TI-2025-42138 Signal K Server vulnerable to JWT Token Theft via WebSocket Enumeration and Unauthenticated Polling CVSS 3.1CRITICAL 9.1
  • TI-2025-42657 Signal K Server Vulnerable to Access Request Spoofing CVSS 3.1HIGH 8.8
  • TI-2026-18939 RCE - Command Injection in Signal K set-system-time plugin CVSS 3.1CRITICAL 10.0
  • TI-2025-42137 Signal K Server Vulnerable to Remote Code Execution via Malicious npm Package CVSS 4.0HIGH 7.3
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences