CVE-2025-39663: Cross-Site Scripting (XSS) vulnerability in Checkmk's distributed monitoring allows a compromised remote site to…
CVE-2025-39663 · Severity: high · CVSS 8.4 · Published 2025-10-30
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).
No. Junglewise Threat Intelligence has no report of CVE-2025-39663 being exploited in the wild.
How severe is CVE-2025-39663?
High severity, with a CVSS score of 8.4, published 30 October 2025.
Which products and versions are affected?
Checkmk. The advisory does not name versions.
Is there a fix for CVE-2025-39663?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2025-39663?
Check whether you run Checkmk. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.