CVE-2026-34083 MEDIUM

CVE-2026-34083: signalk-server: OAuth Authorization Code Theft via Unvalidated Host Header in OIDC Flow

Vendor Signalk
Product signalk-server
Weakness CWE-346 · Origin validation
Published April 2, 2026
Last update April 2, 2026

CVSS base score

6.1/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality Low
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 2, 2026 CVE published
April 2, 2026 Record updated