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CVE-2026-23920

Host and event action script regex validation can be bypassed in certain situations, leading to potential command injection

No known exploitation. EPSS puts it in the 20th percentile. A vendor fix is available.

CVSS 3.18.8HighEPSS percentile20th0.3% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFixVendor fixNo build named by the sources

Published Updated Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Steps

Written by AI from the record
  1. Check whether you run Zabbix and whether host or event actions use script input validation.
  2. Upgrade Zabbix to 7.0.22.
  3. If upgrading is delayed, replace ^ and $ in affected validation rules with \A and \z.
  4. Review who can edit or trigger action scripts and remove unnecessary access.
Vendor advisory Usually a quick update
Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

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.

In plain language

Written by AI from the record

Zabbix installations not yet updated to 7.0.22 should be reviewed, because a logged-in user may be able to run unwanted commands on the server.

Authenticated command injection in Zabbix host and event action scripts: multiline regex validation permits newline-based bypasses when administrators use ^ and $ anchors.

If you're affected

  • Server command execution
  • Monitoring system takeover
  • Service disruption
  • Sensitive data exposure

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS20th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.3% chance of exploitation activity in the next 30 days, which ranks it in the 20th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

9 events over 170 days, from the signal feeds we watch.

  1. Patch availableworkaround available, record updated
  2. Patch availableworkaround available, record updated
  3. Publishedweakness classified, att&ck mapped

Affected products

And 1 more affected product. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Scored 8.8 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required LowRequires basic user-level privileges
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 2 more references. See all after sign-in

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