XSS in Komari-Monitor Komari

CVE-2025-55300

Komari is a lightweight, self-hosted server monitoring tool designed to provide a simple and efficient solution for monitoring server performance. Prior to 1.0.4-fix1, WebSocket upgrader has disabled origin checking, enabling Cross-Site WebSocket Hijacking (CSWSH) attacks against authenticated users. Any third party website can send requests to the terminal websocket endpoint with browser's cookies, resulting in remote code execution. This vulnerability is fixed in 1.0.4-fix1.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.006 (43.8th percentile) — read the EPSS interpretation.