CVE-2026-23934 PUBLISHED

Frontend DoS via the validate.api.exists action

Assigner: Zabbix
Reserved: 19.01.2026 Published: 18.08.2026 Updated: 18.08.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS Score: 5.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Adjacent	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	Low	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	Zabbix
Product	Zabbix
Versions	Default: unknown affected from 7.4.0 to 7.4.11 (incl.)

Affected Configurations

An authenticated user sending crafted HTTP requests to Zabbix Frontend.

Solutions

Update the affected components to their respective fixed versions.

Credits

Zabbix wants to thank kang999 for submitting this report on the HackerOne bug bounty platform. reporter

References

https://support.zabbix.com/browse/ZBX-28072

Problem Types

CWE-405: Asymmetric Resource Consumption (Amplification) CWE

Impacts

CAPEC-490: Amplification