CVE-2025-39663
HIGHCheckmk < 2.4.0p14, 2.3.0p39, 2.2.0, 2.1.0 - Cross-Site Scripting via Service Output Injection
Title source: llmDescription
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).
References (3)
Core 3
Core References
Vendor Advisory
https://checkmk.com/werk/17998
Exploit, Third Party Advisory
https://github.com/sbaresearch/advisories/tree/82fd27e4570433464c30b35150b197db9a850f4e/2025/SBA-ADV-20250729-01_Checkmk_Cross_Site_Scripting
Exploit, Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2025/Nov/0
Scores
CVSS v3
8.4
EPSS
0.0054
EPSS Percentile
41.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
total
Details
CWE
CWE-80
CWE-79
Status
published
Products (2)
checkmk/checkmk
2.3.0 (39 CPE variants)
checkmk/checkmk
2.4.0 (11 CPE variants)
Published
Oct 30, 2025
Tracked Since
Feb 18, 2026