CVE-2026-20915 — MEDIUM (5.4)

Vulnerability Description

Stored cross-site scripting (XSS) in Checkmk version 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create pending changes to inject malicious JavaScript into the Pending Changes sidebar, which will execute in the browsers of other users viewing the sidebar.

CVSS Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality

LOW

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Checkmk	Checkmk	2.5.0

Related Weaknesses (CWE)

CWE-79

References

https://checkmk.com/werk/19526Vendor Advisory

FAQ

What is CVE-2026-20915?

CVE-2026-20915 is a vulnerability with a CVSS score of 5.4 (MEDIUM). Stored cross-site scripting (XSS) in Checkmk version 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create pending changes to inject malicious JavaScript into the Pending Ch...

How severe is CVE-2026-20915?

CVE-2026-20915 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-20915?

Check the references section above for vendor advisories and patch information. Affected products include: Checkmk Checkmk.