CVE-2026-23923Network attack vector

Unauthenticated service interruption via arbitrary PHP class instantiation

Published Mar 24, 2026 · Updated Mar 24, 2026

Unsafe reflection in the Zabbix Frontend 7.4.0 through 7.4.6 allows remote attackers to interrupt the service via its validate action. The validate action accepts an attacker-controlled class selection and blindly instantiates the selected PHP class instead of restricting it to expected validation classes. Any user able to reach the Frontend can invoke the action without authentication, while the reported consequence is limited to Frontend availability.

CVSS severity6.9
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe reflection in the Zabbix Frontend 7.4.0 through 7.4.6 allows remote attackers to interrupt the service via its validate action. The validate action accepts an attacker-controlled class selection and blindly instantiates the selected PHP class instead of restricting it to expected validation classes. Any user able to reach the Frontend can invoke the action without authentication, while the reported consequence is limited to Frontend availability.

The record

CVE
CVE-2026-23923
Published
Mar 24, 2026
Updated
Mar 24, 2026
Vendor
Zabbix
Product
Zabbix
Classifications
CWE-470, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.4.0 <=7.4.6 changes=[{"at":"7.4.7","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zabbix · Zabbixversion=7.4.0 <=7.4.6 changes=[{"at":"7.4.7","status":"unaffected"}]

Published CVSS scores

6.9ZabbixCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-470Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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