CVE-2025-39663
8.4 · HIGHOverview
CVE-2025-39663 is a high-severity vulnerability affecting checkmk checkmk. It was published on October 30, 2025 and has a CVSS 3.1 base score of 8.4 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.4, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
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).
Remediation
Check the references section for vendor advisories and patches from checkmk. Update checkmk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| checkmk | checkmk | >= 2.0.0, < 2.3.0 | Affected |
References
Frequently Asked Questions
What is CVE-2025-39663?
CVE-2025-39663 is a high-severity vulnerability affecting checkmk checkmk. It was published on October 30, 2025 and has a CVSS 3.1 base score of 8.4 (HIGH).
How severe is CVE-2025-39663?
This vulnerability has a CVSS 3.1 base score of 8.4, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2025-39663?
Check the references section for vendor advisories and patches from checkmk. Update checkmk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-39663?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-39663 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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