Executive brief
Zabbix, a widely-used infrastructure monitoring platform, contains a vulnerability in its email notification OAuth configuration. A Super Administrator can leak the stored OAuth client secret by setting a malicious token endpoint URL, allowing potential credential theft. This vulnerability affects only users with Super Admin privileges but could enable unauthorized access to integrated email services.
Technical details
The vulnerability exists in Zabbix Frontend's OAuth configuration for email media. The 'Client secret' field is hidden after saving for security purposes, but it is not cleared when the 'Token endpoint' is modified. A Super Admin can exploit this by setting a malicious token endpoint that captures the client secret during the OAuth flow. The root cause is insufficient secret rotation logic—the secret should be cleared (forcing the user to re-enter it) whenever the token endpoint changes. The fix resets the client secret whenever the token endpoint value is modified, requiring explicit re-entry by the administrator.
Affected products
- Zabbix Zabbix 7.4.0 to 7.4.8
Timeline
- 2026-08-18: disclosed
- 2026-08-18: patched: Fixed in version 7.4.9