CVE-2026-34083

MEDIUM

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

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 6.1
EPSS 0.0001
EPSS Percentile 3.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-346 CWE-601
Status published
Products (3)
npm/signalk-server 2.20.0 - 2.24.0npm
signalk/signal_k_server < 2.24.0
SignalK/signalk-server < 2.24.0
Published Apr 02, 2026
Tracked Since Apr 02, 2026