8.8High
Zabbix 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.
What this means for your business
- It affects Zabbix. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 22% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Zabbix, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 8.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- CVSS v4
- 7.7
- Weakness
- CWE-78
- Assigned by
- security@zabbix.com
Dates
- Published
- 2026-03-24
- Last modified
- 2026-09-10
- Sources
- NVD
Affected products
- Zabbix Zabbix7.0.0 - 7.0.22, 7.2.0 - 7.2.15, 7.4.0 - 7.4.6
As listed in the NVD configuration data. Not a statement about your estate.