# CVE-2026-23934: Zabbix Frontend denial of service via validate.api.exists

Source: https://junglewise.ai/threats/cve-2026-23934-zabbix-frontend-denial-of-service-via-validate-api-exists  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-18. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-23934 · Severity: medium · CVSS 6.5 · Published 2026-08-18

Zabbix Frontend is a web-based monitoring and alerting platform used by organizations to track infrastructure health. An authenticated user can send specially crafted requests to the validate.api.exists endpoint, causing excessive CPU consumption on the webserver and making the monitoring system unresponsive to legitimate traffic.

Technologies: [Zabbix Frontend](https://junglewise.ai/threats/technologies/frontend), [Zabbix](https://junglewise.ai/threats/technologies/zabbix). Vendors: [Zabbix](https://junglewise.ai/threats/vendors/zabbix).

## Quick answers

**Is CVE-2026-23934 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-23934 being exploited in the wild.

**How severe is CVE-2026-23934?** Medium severity, with a CVSS score of 6.5, published 18 August 2026.

**Which products and versions are affected?** Zabbix Frontend 7.4.0 - 7.4.11.

**Is there a fix for CVE-2026-23934?** A patch was published on 2026-08-18: Fixed in version 7.4.12 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-23934 attacked?** It is attacked from the adjacent network, in a web application.

**Am I affected by CVE-2026-23934?** Check whether you run Zabbix Frontend or Zabbix at an affected version. 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

This vulnerability is a denial-of-service condition in the Zabbix Frontend validate.api.exists action caused by inefficient request processing. The attack requires authentication and involves sending crafted HTTP requests that trigger disproportionate CPU load on the Frontend webserver. An authenticated attacker can exploit this to make the monitoring interface unavailable. The vulnerability affects Zabbix Frontend versions 7.4.0 through 7.4.11 and has been patched in version 7.4.12.

## Affected products

- Zabbix Frontend 7.4.0 - 7.4.11

## Timeline

- 2026-08-18: disclosed
- 2026-08-18: patched: Fixed in version 7.4.12

## References

- [https://support.zabbix.com/browse/ZBX-28072](https://support.zabbix.com/browse/ZBX-28072)

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