---
id: CVE-2026-20915
title: >-
  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 …
summary: >-
  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 …
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: checkmk
product: checkmk
affected:
  - checkmk = 2.5.0
published: '2026-03-31'
updated: '2026-07-25'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20915'
references:
  - url: 'https://checkmk.com/werk/19526'
    label: security@checkmk.com
tags:
  - nvd
epss: 0.00147
epssPercentile: 0.03219
ingestedAt: '2026-07-25T10:53:53.754Z'
---

## Overview

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.

## Affected

- `checkmk = 2.5.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.