CVE-2026-34083CWE-346CWE-601

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

Medium · published April 2, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
3.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00142 · 3.2th percentile
Weaknesses
CWE-346 · Origin Validation Error; CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
Published
2026-04-02T16:14Z
EPSS history
Timeline
  • 02 APR 16:14Z
    signalk-server: OAuth Authorization Code Theft via Unvalidated Host Header in OIDC Flow
    cvelistv5