CVE-2025-64999: Checkmk GmbH Checkmk

Cross-site scripting in HTML logs of Synthetic Monitoring test services

CVSS 7.3 HighEPSS 0.0017 · 6th percentile

Published by the CVE Program (CNA: Checkmk) at 26 Feb 2026, 10:26 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Checkmk GmbH	Checkmk	affected 2.4.0 to before 2.4.0p22 semver affected 2.3.0 to before 2.3.0p43 semver Other versions: unaffected

Identifiers

CVE-2025-64999

CNA

Checkmk

Weakness (CWE)

CWE-79

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
7.3	High	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:L/SA:N	CNA (Checkmk)

CISA KEV Not listed.
EPSS 0.0017, the 6th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 26 Feb 2026. New records show when each source confirmed them.

Sources

References from the CNA

checkmk.com/werk/19238 vendor-advisory
github.com/sbaresearch/advisories/tree/e72ce9bb6b9ffffc1fc35e4d8152ad153293c851/2025/SBA-ADV-20251118-01_Checkmk_Cross_Site_Scripting third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.