Resource exhaustion in Signalk Signal K Server
CVE-2026-39320
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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (37.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.004 · change: -0.002
Affected products
- Signalk Signal K Server
- Signalk Signalk-Server — versions < 2.25.0
Weakness classification (CWE)
References
- github.com/SignalK/signalk-server/security/advisories/GHSA-7gcj-phff-2884 (Exploit, Vendor Advisory)
- github.com/SignalK/signalk-server/pull/2568 (Patch, Issue Tracking)
- github.com/SignalK/signalk-server/commit/215d81eb700d5419c3396a0fbf23f2e246dfac… (Patch)
- github.com/SignalK/signalk-server/releases/tag/v2.25.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-39320?
- CVE-2026-39320 is a high-severity vulnerability in Signalk Signal K Server, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-04-21.
- How severe is CVE-2026-39320?
- High severity. CVSS v3 base score is 7.5 out of 10.