# CVE-2025-66398

## Summary

- **CVE ID:** CVE-2025-66398
- **Severity:** CRITICAL
- **CVSS Score:** 9.7 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H)
- **CWE:** CWE-78, CWE-913
- **Published:** Jan 1, 2026
- **Last Modified:** Mar 13, 2026

## 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 — signalk-server (< 2.19.0)

## References

- [CNA](https://github.com/SignalK/signalk-server/security/advisories/GHSA-w3x5-7c4c-66p9)
- [CNA](https://github.com/SignalK/signalk-server/releases/tag/v2.19.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 20.13%
- **EPSS Percentile:** 97.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._