RCE in Signalk Signal K Server
CVE-2025-66398
Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.19.0, an unauthenticated attacker can pollute the internal state (`restoreFilePath`) of the server via the `/skServer/validateBackup` endpoint. This allows the attacker to hijack the administrator's "Restore" functionality to overwrite critical server configuration files (e.g., `security.json`, `package.json`), leading to account takeover and Remote Code Execution (RCE). Version 2.19.0 patches this vulnerability.
Vulnerability class: Command Injection (OS Command Injection)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.199 (97.4th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.199 · newest: 0.199 · change: 0.000
Affected products
- Signalk Signal K Server
- Signalk Signalk-Server — versions < 2.19.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/SignalK/signalk-server/security/advisories/GHSA-w3x5-7c4c-66p9 (Exploit, Vendor Advisory)
- github.com/SignalK/signalk-server/releases/tag/v2.19.0 (Release Notes)
Frequently asked questions
- What is CVE-2025-66398?
- CVE-2025-66398 is a critical-severity vulnerability in Signalk Signal K Server, classified under OS Command Injection. CVSS score: 9.6/10. Published 2026-01-01.
- How severe is CVE-2025-66398?
- Critical severity. CVSS v3 base score is 9.6 out of 10.
- Is CVE-2025-66398 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.