CVE-2025-39663

High · 8.4

CVSS

8.4

EPSS

0.6%

Published

Oct 30, 2025

CISA due date

—

The record

Cross-Site Scripting (XSS) vulnerability in Checkmk's distributed monitoring allows a compromised remote site to inject malicious HTML code into service outputs in the central site. Affecting Checkmk before 2.4.0p14, 2.3.0p39, 2.2.0 and 2.1.0 (eol).

Affected packages

Ecosystem	Package	Introduced	Fixed