Is CVE-2026-33456 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-33456 being exploited in the wild.

How severe is CVE-2026-33456?

High severity, with a CVSS score of 7.6, published 10 April 2026.

Which products and versions are affected?

Checkmk Checkmk < 2.5.0b4, < 2.4.0p26.

Is there a fix for CVE-2026-33456?

A patch was published on 2026-03-23: Vendor released fix in versions 2.5.0b4 and 2.4.0p26 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-33456 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-33456?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-33456: Checkmk Livestatus injection in notification test mode

Q: Which products and versions are affected?

Checkmk Checkmk < 2.5.0b4, < 2.4.0p26.

Q: Is there a fix for CVE-2026-33456?

A patch was published on 2026-03-23: Vendor released fix in versions 2.5.0b4 and 2.4.0p26 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-33456 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-33456?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-33456 · Severity: high · CVSS 7.6 · Published 2026-04-10

Checkmk is an IT infrastructure monitoring solution used to track the health of servers and networks. A security flaw in its notification testing feature allows authorized users to bypass intended restrictions and execute unauthorized commands within the monitoring database. This could allow a user to view sensitive monitoring data or disrupt the availability of the monitoring service.

Quick answers

Is CVE-2026-33456 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-33456 being exploited in the wild.
How severe is CVE-2026-33456?: High severity, with a CVSS score of 7.6, published 10 April 2026.
Which products and versions are affected?: Checkmk Checkmk < 2.5.0b4, < 2.4.0p26.
Is there a fix for CVE-2026-33456?: A patch was published on 2026-03-23: Vendor released fix in versions 2.5.0b4 and 2.4.0p26 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-33456 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-33456?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A Livestatus injection vulnerability exists in Checkmk's notification test mode due to improper neutralization of delimiters (CWE-140). The application fails to properly sanitize user-supplied service description values before interpolating them into Livestatus queries. An authenticated attacker with access to the notification test page can provide a crafted service description to inject and execute arbitrary Livestatus commands. This can lead to unauthorized data retrieval or service disruption. The issue is resolved in versions 2.5.0b4 and 2.4.0p26.

Affected products

Checkmk Checkmk < 2.5.0b4, < 2.4.0p26

Timeline

2026-03-23: patched: Vendor released fix in versions 2.5.0b4 and 2.4.0p26
2026-04-10: disclosed: Initial CVE publication

References

https://checkmk.com/werk/17989

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