High severity · published Mar 24, 2026
CVE-2026-23920
Host and event action script regex validation can be bypassed in certain situations, leading to potential command injection
8.8
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZA
Zabbix · Zabbix
7.0.0 through 7.0.21; 7.2.0 through 7.2.14; 7.4.0 through 7.4.5 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23920
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-23920
Vendor Advisory
https://support.zabbix.com/browse/ZBX-27639
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