Skip to content
OpenAdvisories
Medium · 6.1 CVE-2026-34083 EUVD-2026-18376GHSA-cxj8-ggf2-p57c

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

Published Apr 2, 2026 · Updated Apr 2, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
SignalK signalk-server < 2.24.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm signalk-server >= 2.20.0, < 2.24.0 2.24.0 GHSA-cxj8-ggf2-p57c

References