Signal K Server: Privilege Escalation by Admin Role Injection via /enableSecurity

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-33950: 0.43% estimated exploitation activity in the next 30 days; percentile 37.78 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary According to SignalK's security documentation, when a server is first initialized without security enabled, the /skServer/enableSecurity endpoint is intentionally exposed to allow the owner to set up the initial admin account. This initial open access is by design. However, the critical vulnerability is that this route is never deregistered or disabled after the initial successful setup. Even after the genuine administrator has created their account, restarted the server, and activated token security, the /skServer/enableSecurity route remains perpetually open. Furthermore, the endpoint explicitly trusts the type field provided in the request body, passing it directly into the server's security configuration without validation. Because the route remains permanently listening, any unauthenticated user can call this endpoint at any time to silently inject a new, fully privileged admin account alongside the legitimate ones. Vulnerable Root Cause File: src/serverroutes.ts (Lines…

Published by the source

3 Apr 2026, 21:37 UTC

Last modified by the source

3 Apr 2026, 21:56 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-x8hc-fqv3-7gwf

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-x8hc-fqv3-7gwf

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-x8hc-fqv3-7gwf

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# Patch Next advisory brief: CVE-2026-33950

Advisory: Signal K Server: Privilege Escalation by Admin Role Injection via /enableSecurity
IDs: CVE-2026-33950, GHSA-x8hc-fqv3-7gwf
Record: https://patchnext.com/advisories/cve-2026-33950 (revision 3, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: signalk-server 2.24.0-beta.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm signalk-server: affected < 2.24.0-beta.4; fixed in 2.24.0-beta.4

## Suggested inspection (read-only)
- `npm ls signalk-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on signalk-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x8hc-fqv3-7gwf (GitHub-reviewed advisory GHSA-x8hc-fqv3-7gwf lists affected ranges: npm signalk-server >=0 <2.24.0-beta.4)
- Verified: https://osv.dev/vulnerability/GHSA-x8hc-fqv3-7gwf (OSV record GHSA-x8hc-fqv3-7gwf lists affected ranges: npm signalk-server >=0 <2.24.0-beta.4 (fixed))

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