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TI-2026-26405 Aliases CVE-2026-34083GHSA-cxj8-ggf2-p57c

signalk-server: OAuth Authorization Code Theft via Unvalidated Host Header in OIDC Flow

Priority MEDIUM 60CWE-346Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-346 and CWE-601.

Summary

Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.24.0, SignalK Server contains a code-level vulnerability in its OIDC login and logout handlers where the unvalidated HTTP Host header is used to construct the OAuth2 redirect_uri. Because the redirectUri configuration is silently unset by default, an attacker can spoof the Host header to steal OAuth authorization codes and hijack user sessions in realistic deployments as The OIDC provider will then send the authorization code to whatever domain was injected. This issue has been patched in version 2.24.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00116 1st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed signalk-server (SignalK): 2.24.0signalk-server (npm): 2.24.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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

VendorProductAffected versionsFixed inStatusSource
SignalKsignalk-serverbefore 2.24.02.24.0Patch availableCNA
—signalk-server (npm)2.20.0 to before 2.24.02.24.0Patch availableGHSA-cxj8-ggf2-p57c
  • signalk-server VendorSignalK Affected before 2.24.0 Fixed in 2.24.0 Patch available CNA
  • signalk-server (npm) Vendor— Affected 2.20.0 to before 2.24.0 Fixed in 2.24.0 Patch available GHSA-cxj8-ggf2-p57c

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:signalk:signal_k_server:*:*:*:*:*:*:*:*before 2.24.0VulnerableSignalK
  • cpe:2.3:a:signalk:signal_k_server:*:*:*:*:*:*:*:* Versions before 2.24.0 Vulnerable ·SignalK

Remediation

  • Fix · CNA signalk-server (SignalK) Fixed in 2.24.0
  • Fix · GHSA-cxj8-ggf2-p57c signalk-server (npm) Fixed in 2.24.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34083
  2. 2026-10-03 Alias added: GHSA-cxj8-ggf2-p57c

References

Exploit 1

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-2026-30295 Signal K Server's WebSocket Login Endpoint Lacks Rate Limiting (Credential Brute-Force) CVSS 4.0HIGH 8.7
  • 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
See all 13 →

Sources

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