# CVE-2026-33951: SignalK Signal K Server authentication bypass in sourcePriorities endpoint

Source: https://junglewise.ai/threats/cve-2026-33951-signalk-signal-k-server-authentication-bypass-in-sourcepriorities  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-02. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-33951 · Severity: high · CVSS 7.5 · Published 2026-04-02

Signal K Server is a central hub used on boats to manage navigation and sensor data. A security flaw allows unauthorized users to remotely change which data sources (like GPS or AIS) the boat trusts. This could allow an attacker to manipulate critical navigation information, and these changes remain in effect even if the system is restarted.

Technologies: [signalk-server (npm)](https://junglewise.ai/threats/technologies/signalk-server). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-33951 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33951 being exploited in the wild.

**How severe is CVE-2026-33951?** High severity, with a CVSS score of 7.5, published 2 April 2026.

**Which products and versions are affected?** signalk-server (npm) SEMVER:introduced=0,fixed=2.24.0-beta.1.

**Is there a fix for CVE-2026-33951?** Yes. signalk-server (npm): upgrade to 2.24.0-beta.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-33951 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-33951?** Check whether you run signalk-server (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- signalk-server (npm): upgrade to 2.24.0-beta.1 or later

  ```sh
  npm install signalk-server@2.24.0-beta.1
  ```


## Technical details

Signal K Server prior to version 2.24.0-beta.1 exposes an unauthenticated HTTP PUT endpoint at `/signalk/v1/api/sourcePriorities`. The vulnerable handler in `src/serverroutes.ts` lacks authentication and authorization middleware, directly assigning the user-controlled request body to the server's `sourcePriorities` configuration. Because the server immediately applies these changes and persists them to the settings file on disk, an attacker can remotely influence which sensor data (GPS, AIS, etc.) is prioritized by the system. This manipulation survives server restarts and requires no valid credentials or user interaction.

## Affected products

- SignalK Signal K Server < 2.24.0-beta.1

## Identifiers

- CVE-2026-33951
- GHSA-gfmv-vh34-h2x5

## Timeline

- 2026-03-23: patched: Version 2.24.0-beta.1 tagged on GitHub
- 2026-04-01: advisory: GitHub Security Advisory published
- 2026-04-02: disclosed: CVE published to NVD

## References

- [https://github.com/SignalK/signalk-server/releases/tag/v2.24.0-beta.1](https://github.com/SignalK/signalk-server/releases/tag/v2.24.0-beta.1)
- [https://github.com/SignalK/signalk-server/security/advisories/GHSA-gfmv-vh34-h2x5](https://github.com/SignalK/signalk-server/security/advisories/GHSA-gfmv-vh34-h2x5)

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