CVE-2026-123807 Signal K resources API path traversal can disclose the JWT signing secret and enable remote code execution
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-123807?
CVE-2026-123807 is a critical vulnerability in @signalk resources-provider, published on 9 Nov 2026.
Official description
Signal K Server is a server application that runs on a central hub in a boat. From 2.0.0 until 2.34.0 for Signal K Server and from 1.0.0 until 1.5.3 for @signalk/resources-provider, the v2 REST route GET /signalk/v2/api/resources/:resourceType/:resourceId accepts an unsafe resourceId that can escape the intended resource directory. The route passes the attacker-controlled resourceId through src/api/resources/index.ts to FileStore.getResource() in packages/resources-provider-plugin/src/filestorage.ts without adequate path containment, allowing arbitrary JSON files reachable by the server to be read. Related PUT and DELETE resource operations can write or delete files outside the storage root. Deployments with allow_readonly enabled permit anonymous reads, while other deployments require a readonly user token. Reading security.json exposes the HS256 JWT signing secret and password hashes, allowing an attacker to forge an administrator token. Administrative access to POST /skServer/providers can then create an Execute provider that runs commands with the server process privileges and persists its configuration across restarts. This issue is fixed in Signal K Server 2.34.0 and @signalk/resources-provider 1.5.3.
Weakness: CWE-22
Which versions are affected by CVE-2026-123807?
2 open source packages ship an affected version, including @signalk/resources-provider and signalk-server.
| Package | Affected | Fixed in |
|---|---|---|
@signalk/resources-provider npm | From 1.0.0 | 1.5.3 |
signalk-server npm | From 2.0.0 | 2.34.0 |
How do I fix CVE-2026-123807?
Upgrade @signalk/resources-provider to 1.5.3 or later.
Is CVE-2026-123807 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-123807 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-4xm8-rg9h-jhq2.