CVE-2026-24891: openITCOCKPIT is an open source monitoring tool built for different monitoring engines like Nagios, Naemon and Prometheus. Versions 5.3.1 and below co...

Description

openITCOCKPIT is an open source monitoring tool built for different monitoring engines like Nagios, Naemon and Prometheus. Versions 5.3.1 and below contain an unsafe deserialization sink in the Gearman worker implementation. The worker function registered as oitc_gearman calls PHP's unserialize() on job payloads without enforcing class restrictions or validating data origin. While the intended deployment assumes only trusted internal components enqueue Gearman jobs, this trust boundary is not enforced in application code. In environments where the Gearman service or worker is exposed to untrusted systems, an attacker may submit crafted serialized payloads to trigger PHP Object Injection in the worker process. This vulnerability is exploitable when Gearman listens on non-local interfaces, network access to TCP/4730 is unrestricted, or untrusted systems can enqueue jobs. Default, correctly hardened deployments may not be immediately exploitable, but the unsafe sink remains present in code regardless of deployment configuration. Enforcing this trust boundary in code would significantly reduce risk and prevent exploitation in misconfigured environments. This issue has been fixed in version 5.4.0.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.36%

27.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-502

Affected Software

Vendor	Product	Versions
It-Novum	Openitcockpit	< 5.4.0

References

https://github.com/openITCOCKPIT/openITCOCKPIT/releases/tag/openITCOCKPIT-5.4.0Product, Release Notes
https://github.com/openITCOCKPIT/openITCOCKPIT/security/advisories/GHSA-x4mq-8gfg-frc4Exploit, Mitigation, Vendor Advisory

Timeline

Published: Feb 20, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-24891?

openITCOCKPIT is an open source monitoring tool built for different monitoring engines like Nagios, Naemon and Prometheus. Versions 5.3.1 and below contain an unsafe deserialization sink in the Gearman worker implementation. The worker function registered as oitc_gearman calls PHP's unserialize() on job payloads without enforcing class restrictions or validating data origin. While the intended deployment assumes only trusted internal components enqueue Gearman jobs, this trust boundary is not enforced in application code. In environments where the Gearman service or worker is exposed to untrusted systems, an attacker may submit crafted serialized payloads to trigger PHP Object Injection in the worker process. This vulnerability is exploitable when Gearman listens on non-local interfaces, network access to TCP/4730 is unrestricted, or untrusted systems can enqueue jobs. Default, correctly hardened deployments may not be immediately exploitable, but the unsafe sink remains present in code regardless of deployment configuration. Enforcing this trust boundary in code would significantly reduce risk and prevent exploitation in misconfigured environments. This issue has been fixed in version 5.4.0.

How severe is CVE-2026-24891?

CVE-2026-24891 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2026-24891?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.