Description
SSH private keys of the "Remote alert handlers (Linux)" rule were exposed in the rule page's HTML source in Checkmk <= 2.4.0p18 and all versions of Checkmk 2.3.0. This potentially allowed unauthorized triggering of predefined alert handlers on hosts where the handler was deployed.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Checkmk | Checkmk | 2.4.0 – < 2.4.0p18, 2.3.0 | 2.4.0p18 |
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-2025-2893 Checkmk: Mehrere Schwachstellen ermöglichen Offenlegung von Informationen BSI CERT-Bund (WID) · Dec 18, 2025