The action can be invoked by any user able to reach Frontend.
"}],"value":"The action can be invoked by any user able to reach Frontend."}],"credits":[{"lang":"en","type":"reporter","value":"Zabbix wants to thank pitticus for submitting this report on the HackerOne bug bounty platform."}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"An unauthenticated attacker can exploit the Frontend 'validate' action to blindly instantiate arbitrary PHP classes. The impact depends on environment setup but appears limited at this time.
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"}],"value":"Update the affected components to their respective fixed versions."}],"source":{"discovery":"EXTERNAL"},"title":"Unauthenticated arbitrary PHP class instantiation","x_generator":{"engine":"Vulnogram 1.0.1"}}},"cveMetadata":{"assignerOrgId":"72de3e22-0555-4a0d-ae81-9249e0f0a1e8","assignerShortName":"Zabbix","cveId":"CVE-2026-23923","datePublished":"2026-03-24T18:29:23.165Z","dateReserved":"2026-01-19T14:02:54.327Z","dateUpdated":"2026-03-25T19:25:01.128Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-24 19:16:50","lastModifiedDate":"2026-09-10 21:16:44","problem_types":["CWE-470","CWE-470 CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')"],"metrics":{"cvssMetricV40":[{"source":"security@zabbix.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":6.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-03-25T19:24:53.942052Z","id":"CVE-2026-23923","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:zabbix:zabbix:*:*:*:*:*:*:*:*","versionStartIncluding":"7.4.0","versionEndExcluding":"7.4.7","matchCriteriaId":"BFA15249-079B-4FF1-94D1-9392C85B58BF"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"23923","Ordinal":"1","Title":"Unauthenticated arbitrary PHP class instantiation","CVE":"CVE-2026-23923","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"23923","Ordinal":"1","NoteData":"An unauthenticated attacker can exploit the Frontend 'validate' action to blindly instantiate arbitrary PHP classes. The impact depends on environment setup but appears limited at this time.","Type":"Description","Title":"Unauthenticated arbitrary PHP class instantiation"}]}}}