CVE-2026-23933 Hardcoded session key in Zabbix 7.4

High 7.7 Published 18 Aug 2026 Updated 19 Aug 2026

Attackers can forge session cookies to gain unauthorized access in Zabbix deployments using SAML and guest users due to a hardcoded key.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-23933?

CVE-2026-23933 is a high-severity 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

In Zabbix 7.4 the cryptographic key used for signing Frontend sessions has been erroneously written to the database seed. Currently the only known exploitation scenario is for deployments that utilize both - SAML authentication and guest users. In such cases the key can be used to forge valid session cookies, potentially leading to unauthorized access. For other Zabbix deployments this does not have a known impact.

Weakness: CWE-259

Which versions are affected by CVE-2026-23933?

It affects 1 product.

Products include Zabbix Zabbix.

How do I fix CVE-2026-23933?

No fix has been published for CVE-2026-23933 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-23933 being exploited?

There is no known exploitation of CVE-2026-23933 in the wild and no public exploit code.

All Zabbix Zabbix vulnerabilities

Sources

Also known as GHSA-5j5m-c26m-fvc8, UBUNTU-CVE-2026-23933.