CVE-2026-23934 Frontend DoS via the validate.api.exists action
An authenticated user can cause denial of service on the Zabbix Frontend webserver by sending crafted requests to the validate.api.exists action.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-23934?
CVE-2026-23934 is a medium-severity denial of service vulnerability in Zabbix Zabbix, published on 18 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An authenticated user is able to cause disproportionate CPU load on the Frontend webserver by sending specifically crafted requests to the Frontend validate.api.exists action, leading to potential denial of service.
Weakness: CWE-405
Which versions are affected by CVE-2026-23934?
It affects 1 product.
Products include Zabbix Zabbix.
How do I fix CVE-2026-23934?
No fix has been published for CVE-2026-23934 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-23934 being exploited?
There is no known exploitation of CVE-2026-23934 in the wild and no public exploit code.
Other vulnerabilities in Zabbix Zabbix
Sources
Also known as GHSA-j6gv-xg9q-8h4p, UBUNTU-CVE-2026-23934.