CVE-2025-64999
Medium
Description
Improper neutralization of input in Checkmk versions 2.4.0 before 2.4.0p22, and 2.3.0 before 2.3.0p43 allows an attacker that can manipulate a host's check output to inject malicious JavaScript into the Synthetic Monitoring HTML logs, which can then be accessed via a crafted phishing link.
SeverityMedium
CVSS5.4
Exploit probability—
ProductCheckmk
PublishedFeb 26, 2026
First seenFeb 26, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| checkmk checkmk | 2.3.0, 2.4.0 | — |
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