dbcve.org
Signal K ServerApplication · Signalk

CVE-2026-33951

HIGH · 7.5 CVSS v3.1 Published 2026-04-02
Fix available
A fix is available. Upgrade to 2.24.0 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.24.0-beta.1, the SignalK Server exposes an unauthenticated HTTP endpoint that allows remote attackers to modify navigation data source priorities. This endpoint, accessible via PUT /signalk/v1/api/sourcePriorities, does not enforce authentication or authorization checks and directly assigns user-controlled input to the server configuration. As a result, attackers can influence which GPS, AIS, or other sensor data sources are trusted by the system. The changes are immediately applied and persisted to disk, allowing the manipulation to survive server restarts. This issue has been patched in version 2.24.0-beta.1.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Signal K Server prior to version 2.24.0-beta.1 exposes an unauthenticated HTTP PUT endpoint at /signalk/v1/api/sourcePriorities that allows remote attackers to modify navigation data source priorities (GPS, AIS, sensors) without any authentication or authorization. The endpoint directly assigns user-controlled input to server configuration and persists changes to disk, allowing manipulation to survive server restarts.

MitigationUpgrade to Signal K Server version 2.24.0-beta.1 or later to apply the patch; if immediate patching is not feasible, restrict network access to the vulnerable endpoint via firewall or network segmentation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Signal K ServerApplication
Affected:< 2.24.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Signal K Server installation
    Locate Signal K Server installation and determine its version. Common methods: check package.json version if self-hosted, check Docker image tag, or query the server API at /signalk/ for the 'version' field in the response
    Affected if Server version is < 2.24.0 (or version is unknown/unretrievable)
  2. Verify the vulnerable endpoint exists
    Send an unauthenticated HTTP PUT request to http://<server>:8080/signalk/v1/api/sourcePriorities with a test payload such as {"test":1} and observe the response code
    Affected if The request returns HTTP 200 OK or any success response without requiring authentication credentials
  3. Inspect current sourcePriorities configuration
    Check the Signal K Server configuration file (typically at ~/.signalk/config.json or in the server's data directory) for the 'sourcePriorities' key. Also, retrieve it via GET /signalk/v1/api/sourcePriorities without authentication
    Affected if The endpoint returns configuration data without auth, or the config file contains sourcePriorities with unexpected/modified values you did not set
  4. Review access logs for unauthorized PUT requests
    Examine Signal K Server access logs (check logs/ directory or Docker logs) for entries matching PUT requests to /signalk/v1/api/sourcePriorities from unexpected IP addresses or at unexpected times

You are affected if Signal K Server version is below 2.24.0 AND the /signalk/v1/api/sourcePriorities endpoint responds to unauthenticated PUT requests.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.24.0 or later
Fixed in 2.24.0
Interim mitigation

Upgrade to Signal K Server version 2.24.0-beta.1 or later to apply the patch; if immediate patching is not feasible, restrict network access to the vulnerable endpoint via firewall or network segmentation.

Recommended fix High confidence

2.24.0-beta.1

  1. Upgrade Signal K Server to version 2.24.0-beta.1 or later by stopping the server, updating the installation, and restarting the service

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Signal K Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,980
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,168.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-33951 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33951 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data