CVE-2015-4026: The pcntl_exec implementation in PHP before 5.4.41, 5.5.x before 5.5.25, and 5.6.x before 5.6.9 truncates a...

Security readout for executives and security teams

This is an old PHP flaw where a filename containing a null byte could be cut short before execution. If an application lets an attacker influence the path passed to pcntl_exec, extension checks may be bypassed and an unexpected file may run. Exposure is most plausible on legacy PHP 5.x systems running affected versions and application code that passes attacker-influenced pathnames into pcntl_exec. Systems using vendor PHP packages from referenced distributions should verify the relevant 2015 updates were applied. Prioritize remediation if any legacy PHP 5.x environment still exists, especially on externally reachable systems. This is not flagged as actively exploited in the supplied evidence, but affected runtimes are obsolete and the impact can include unintended file execution. Mitigation focus: Upgrade PHP to 5.4.41, 5.5.25, 5.6.9, or later fixed releases.; Apply vendor PHP security updates from Red Hat, Debian, openSUSE, Fedora, Apple, Oracle, or your distribution.; Remove or isolate legacy PHP 5.x runtimes where upgrades are not practical..

Prepared

Jun 13, 2026, 22:39 UTC (UTC+00:00)

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