# Signal K resources API path traversal and RCE

Source: https://junglewise.ai/threats/signal-k-resources-api-path-traversal-can-disclose-the-jwt-signing-0c6398ee  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-30. Updated: 2026-10-30  
License: CC BY 4.0 with a link back

Severity: critical · CVSS 9.8 · Published 2026-10-30

Signal K is a standardized marine data format and server for sharing navigation and vessel data. An unauthenticated attacker can read sensitive files including the JWT signing secret, forge admin credentials, and execute arbitrary commands on the server with persistent effects across restarts. This requires the optional read-only anonymous access feature to be enabled.

Technologies: [signalk-server (npm)](https://junglewise.ai/threats/technologies/signalk-server). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Signal K](https://junglewise.ai/threats/vendors/signal-k).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Critical severity, with a CVSS score of 9.8, published 30 October 2026.

**Which products and versions are affected?** @signalk/resources-provider (npm) >= 1.0.0, < 1.5.3, SEMVER:introduced=1.0.0,fixed=1.5.3; signalk-server (npm) >= 2.0.0, < 2.34.0, SEMVER:introduced=2.0.0,fixed=2.34.0; Signal K all releases before 2.34.0.

**Is there a fix for This vulnerability?** Yes. @signalk/resources-provider (npm): upgrade to 1.5.3 or later; signalk-server (npm): upgrade to 2.34.0 or later. Until then: Disable the `allow_readonly` configuration option (read-only anonymous access) if not required. Restrict network access to the Signal K server to trusted users and networks. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network.

**Am I affected?** Check whether you run @signalk/resources-provider (npm), signalk-server (npm) or Signal K 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/resources-provider (npm): upgrade to 1.5.3 or later

  ```sh
  npm install @signalk/resources-provider@1.5.3
  ```

- signalk-server (npm): upgrade to 2.34.0 or later

  ```sh
  npm install signalk-server@2.34.0
  ```


Disable the `allow_readonly` configuration option (read-only anonymous access) if not required. Restrict network access to the Signal K server to trusted users and networks.

## Technical details

The REST API endpoint `/signalk/v2/api/resources/:resourceType/:resourceId` passes the resourceId parameter directly to path operations without validation, allowing percent-encoded path traversal (`..%2F`) to escape the storage directory. An attacker reads `config/security.json` to obtain the HS256 JWT signing secret, then forges an admin token to reach the provider creation endpoint, which executes arbitrary shell commands via the `Execute` provider type instantiated at creation time.

## Affected products

- Signal K Signal K all releases before 2.34.0

## Timeline

- 2026-10-30: disclosed: GHSA-4xm8-rg9h-jhq2 published

## Related threats

- [Signal K Server buffered logs exposure in unauthenticated WebSocket](https://junglewise.ai/threats/signal-k-server-buffered-logs-exposed-to-unauthenticated-websocket-b7032aad)
- [Signal K Server SSRF in App Store icon fetcher](https://junglewise.ai/threats/cve-2026-115752-signal-k-server-from-2-28-0-beta-2-before-2-34-0-contains-a)
- [Signal K Server SSRF in remote connection endpoints](https://junglewise.ai/threats/cve-2026-55591-signal-k-server-ssrf-in-remote-connection-endpoints)
- [SignalK Signal K Server brute-force protection bypass in WebSocket login](https://junglewise.ai/threats/cve-2026-41893-signalk-signal-k-server-brute-force-protection-bypass-in)
- [Signal K Server has an Unauthenticated Regular Expression Denial of Service (ReDoS) via WebSocket Subscription Paths](https://junglewise.ai/threats/cve-2026-39320-signal-k-server-has-an-unauthenticated-regular-expression-denial)