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PatchSiren cyber security CVE debrief

CVE-2026-23923 Zabbix CVE debrief

An unauthenticated attacker can exploit the Frontend 'validate' action to blindly instantiate arbitrary PHP classes in Zabbix, potentially leading to code execution. The impact depends on environment setup, especially for versions 7.4.0 through 7.4.7, and appears limited at this time. Defenders should verify exposure, assess potential impacts, and monitor for vendor patches. This vulnerability allows for arbitrary PHP class instantiation, which could lead to various security issues depending on the environment. Zabbix administrators and security teams should assess their exposure and potential impacts.

Vendor
Zabbix
Product
Unknown
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-03-24
Original CVE updated
2026-09-10
Advisory published
2026-03-24
Advisory updated
2026-09-10

Who should care

Zabbix administrators and security teams should assess exposure and potential impacts, especially for versions 7.4.0 through 7.4.7. They should verify potential code execution paths through arbitrary PHP class instantiation, assess environment-specific impacts on Zabbix deployments, and monitor for patches and updates from Zabbix. This includes reviewing the supplied official advisory or CVE record to validate the Z

Why it matters

CVE-2026-23923 allows unauthenticated attackers to exploit Zabbix Frontend, potentially leading to arbitrary PHP class instantiation. Defenders should verify exposure, assess impacts, and monitor for vendor patches.

  • Verify potential code execution paths through arbitrary PHP class instantiation
  • Assess environment-specific impacts on Zabbix deployments
  • Monitor for patches and updates from Zabbix

Technical summary

CVE-2026-23923 allows unauthenticated attackers to exploit the Frontend 'validate' action in Zabbix, potentially instantiating arbitrary PHP classes. This could lead to environment-dependent security issues, including potential code execution paths. The impact appears limited but depends on the specific Zabbix deployment and version, particularly versions 7.4.0 through 7.4.7. Defenders should verify environment-specific impacts, assess exposure, and monitor for patches and updates from Zabbix.

Defensive priority

Defenders should prioritize verifying environment-specific impacts and assessing exposure, especially in Zabbix deployments using version 7.4.0 through 7.4.7.

Recommended defensive actions

  • Verify Zabbix environment exposure, especially for versions 7.4.0 through 7.4.7
  • Assess potential impacts of arbitrary PHP class instantiation
  • Monitor for vendor advisories and patches from Zabbix

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and vector. A vendor advisory is available for Zabbix users.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-23923 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-23923

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-23923 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-23923

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.