SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-64999

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…

HIGH 7.3EPSS 0.14%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0
7.3 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.14% probability · 4th percentile
CISA KEV
Not listed
Weakness
CWE-79
Affected
checkmk/checkmk
Source
security@checkmk.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.