RCE in Zabbix

CVE-2026-23920

Host and event action script input is validated with a regex (set by the administrator), but the validation runs in multiline mode. If ^ and $ anchors are used in user input validation, an injected newline lets authenticated users bypass the check and inject shell commands.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (20.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.3% 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-2026-23920: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

  • Zabbix — versions 7.0.0, 7.2.0, 7.4.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23920?
CVE-2026-23920 is a high-severity vulnerability in Zabbix, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-03-24.
How severe is CVE-2026-23920?
High severity. CVSS v3 base score is 8.8 out of 10.