Description
Stored cross-site scripting in the global settings change log in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an administrator who can change global settings to store malicious HTML or JavaScript in changelog messages that executes in other users' browsers when they view the Activate Changes page or Audit log.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Checkmk | Checkmk | 2.5.0 – < 2.5.0p5, 2.4.0 – < 2.4.0p31, 2.3.0 – < 2.3.0p48, 2.2.0 | 2.5.0p5 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | check-mk | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | check-mk | No fix yet | — |
Advisories 1
- WID-SEC-2026-1817 Checkmk: Mehrere Schwachstellen ermöglichen Cross-Site Scripting BSI CERT-Bund (WID) · Jun 8, 2026
References
- https://checkmk.com/werk/17992 vendor-advisory