What’s Vulnerable › Vulnerabilities

CVE-2025-66398: Signal K Server has Unauthenticated State Pollution leading to Remote Code Execution (RCE)

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 19.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-01-01 · updated 2026-10-07
• Weakness: CWE-78

Description

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.

Affected products

• signalk-server: before 2.19.0 — fixed in 2.19.0

How to fix

Upgrade to a fixed version: signalk-server 2.19.0. Check the vendor advisory for mitigations.

References

• https://github.com/SignalK/signalk-server/releases/tag/v2.19.0
• https://github.com/SignalK/signalk-server/security/advisories/GHSA-w3x5-7c4c-66p9

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