CVE-2026-1199 PUBLISHED

API and Frontend login lockout race condition

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

Zabbix API and Frontend login lockout mechanism has a flaw where several unsuccessful login requests are not properly counted towards the block counter if sent simultaneously, potentially allowing for more password guesses than intended.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 6.9

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

CVSS 4.0

Product Status

Vendor	Zabbix
Product	Zabbix
Versions	Default: unknown affected from 6.0.0 to 6.0.46 (incl.) affected from 7.0.0 to 7.0.27 (incl.) affected from 7.4.0 to 7.4.11 (incl.)

Affected Configurations

An attacker with access to Zabbix Frontend or Zabbix API can perform more password guesses than intended.

Solutions

Update the affected components to their respective fixed versions.

Credits

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

References

https://support.zabbix.com/browse/ZBX-28076

Problem Types

CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') CWE

Impacts

CAPEC-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions