CVE-2026-39320
Signal K Server has an Unauthenticated Regular Expression Denial of Service (ReDoS) via WebSocket Subscription Paths
Impact
Signal K Server is a server application that runs on a central hub in a boat. Versions prior to 2.25.0 are vulnerable to an unauthenticated Regular Expression Denial of Service (ReDoS) attack within the WebSocket subscription handling logic. By injecting unescaped regex metacharacters into the `context` parameter of a stream subscription, an attacker can force the server's Node.js event loop into a catastrophic backtracking loop when evaluating long string identifiers (like the server's self UUID). This results in a total Denial of Service (DoS) where the server CPU spikes to 100% and becomes completely unresponsive to further API or socket requests. Version 2.25.0 contains a fix.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | signalk-server | < 2.25.0 | 2.25.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Signalk | Signal K Server | before 2.25.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-7gcj-phff-2884
- https://github.com/SignalK/signalk-server/security/advisories/GHSA-7gcj-phff-2884
- https://nvd.nist.gov/vuln/detail/CVE-2026-39320
- https://github.com/SignalK/signalk-server/pull/2568
- https://github.com/SignalK/signalk-server/commit/215d81eb700d5419c3396a0fbf23f2e246dfac2d
- https://github.com/SignalK/signalk-server/releases/tag/v2.25.0