CVE-2025-64999
Published:February 26, 2026
Updated:August 02, 2026
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.
Affected Packages
https://github.com/Checkmk/checkmk.git (GITHUB):
Affected version(s) >=v2.3.0p1 <v2.3.0p43Fix Suggestion:
Update to version v2.3.0p43https://github.com/Checkmk/checkmk.git (GITHUB):
Affected version(s) >=v2.4.0p2 <v2.4.0p22-rc1Fix Suggestion:
Update to version v2.4.0p22-rc1Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
LOW
User Interaction
ACTIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
9
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
EPSS
Base Score:
0.14