CVE-2026-41570
HIGHPHPUnit is a testing framework for PHP. In versions 12.5.21 and 13.1.5, PHPUnit forwards PHP INI settings to child processes (used for isolated/PHPT test execution) as -d name=value…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
PHPUnit is a testing framework for PHP. In versions 12.5.21 and 13.1.5, PHPUnit forwards PHP INI settings to child processes (used for isolated/PHPT test execution) as -d name=value command-line arguments without neutralizing INI metacharacters. Because PHP's INI parser interprets " as a string delimiter, ; as the start of a comment, and most importantly a newline as a directive separator, a value containing a newline is parsed by the child process as multiple INI directives. An attacker able to influence a single INI value can therefore inject arbitrary additional directives into the child's configuration, including auto_prepend_file, extension, disable_functions, open_basedir, and others. Setting auto_prepend_file to an attacker-controlled path yields remote code execution in the child process. This issue has been patched in versions 12.5.22 and 13.1.6.
Affected Products
phpunitphpunit_projectDetection & mitigation playbook
Vendor / applianceDetect
Inventory every phpunit_project phpunit deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2026-41570 yet — track the phpunit_project phpunit advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-41570 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-41570. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-41570 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-41570 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.