SB20260325208 - Multiple vulnerabilities in Zabbix

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) SQL Injection: Hibernate (CVE-ID: CVE-2026-23921)

The vulnerability allows a remote user to disclose sensitive information.

The vulnerability exists due to blind SQL injection in the Zabbix API via the sortfield parameter in include/classes/api/CApiService.php when processing API requests. A remote user can send a specially crafted API request to exfiltrate arbitrary database data through time-based techniques, potentially leading to session identifier disclosure and administrator account compromise.

Access to a Zabbix account with API access is required to exploit this vulnerability.

2) Command injection (CVE-ID: CVE-2026-23920)

The vulnerability allows a remote user to execute arbitrary code.

The vulnerability exists due to improper input validation in host and event action script processing when handling regex validation in multiline mode. A remote user can send a specially crafted script input containing a newline character to bypass ^ and $ anchors in administrator-defined regex patterns and inject arbitrary shell commands.

Successful exploitation requires the attacker to have script execution permissions and the target system to use ^ and $ anchors in its input validation regex.

Remediation

Install update from vendor's website.

References

• https://support.zabbix.com/browse/ZBX-27640
• https://support.zabbix.com/browse/ZBX-27639