CVE-2015-4602: The __PHP_Incomplete_Class function in ext/standard/incomplete_class.c in PHP before 5.4.40, 5.5.x before 5...

Security readout for executives and security teams

Older PHP 5 releases can crash, and may allow code execution, when a remote attacker sends data that triggers a type confusion flaw in __PHP_Incomplete_Class handling. The source record names fixed PHP 5.4, 5.5, and 5.6 versions. No cited source confirms active exploitation. Exposure is likely limited to legacy PHP 5 deployments below the fixed versions, including vendor-packaged PHP from affected Linux distributions. Systems most relevant are web-facing PHP applications where remote input can reach the vulnerable runtime behavior. Prioritize remediation for internet-facing or business-critical PHP 5 systems. The age of the flaw reduces surprise risk, but any remaining vulnerable runtime is likely unsupported and may carry broader accumulated exposure. Mitigation focus: Upgrade PHP to 5.4.40, 5.5.24, 5.6.8, or later supported versions.; Apply relevant vendor security updates from Red Hat, Oracle, or your distribution.; Retire unsupported PHP 5 runtimes where business applications allow it..

Prepared

Jun 13, 2026, 14:22 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.