High severity · published Jan 1, 2026
CVE-2025-66398
Signal K Server has Unauthenticated State Pollution leading to Remote Code Execution (RCE)
8.8
CVSS
19.8%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)19.8% · higher than 97% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
signalk-server · SignalK
< 2.19.0 · source: vendor
SK
Signal K Server · Signalk
before 2.19.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-66398
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-66398
Release Notes
https://github.com/SignalK/signalk-server/releases/tag/v2.19.0
Exploit
https://github.com/SignalK/signalk-server/security/advisories/GHSA-w3x5-7c4c-66p9
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