Vulnerability in Zabbix

CVE-2026-23923

An unauthenticated attacker can exploit the Frontend 'validate' action to blindly instantiate arbitrary PHP classes. The impact depends on environment setup but appears limited at this time.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.003 (17.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23923: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23923?
CVE-2026-23923 is a medium-severity vulnerability in Zabbix, classified under Use of Externally-Controlled Input to Select Classes or Code (Unsafe Reflection). CVSS score: 5.3/10. Published 2026-03-24.
How severe is CVE-2026-23923?
Medium severity. CVSS v3 base score is 5.3 out of 10.