CVE-2026-41570

## Impact 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. Sources of INI values that participate in the attack: - `<ini name="…" value="…"/>` entries in `phpunit.xml` / `phpunit.xml.dist` - INI settings inherited from the host PHP runtime via `ini_get_all()` ### Threat Model Exploitation requires the attacker to control the content of an INI value read by PHPUnit. In practice this means write access to the project's `phpunit.xml`, the host `php.ini`, or the PHP binary's environment. The most realistic exposure is [Poisoned Pipeline Execution](https://owasp.org/www-project-top-10-ci-cd-security-risks/CICD-SEC-04-Poisoned-Pipeline-Execution) (PPE): a pull request from an untrusted contributor that modifies `phpunit.xml` to include a newline-containing INI value, executed by a CI system that runs PHPUnit against the PR without isolation. A malicious newline is not visibly distinguishable from a legitimate value in a typical diff review. ### Affected component `PHPUnit\Util\PHP\JobRunner::settingsToParameters()`. ## Patches The fix has two parts: **1. Reject line-break characters** Because a newline or carriage return in an INI value has no legitimate use and is the primitive that enables directive injection, any PHP setting value containing `\n` or `\r` is now rejected with an explicit `PhpProcessException`. This follows the same "visibility over silence" principle applied in [CVE-2026-24765](https://github.com/sebastianbergmann/phpunit/security/advisories/GHSA-vvj3-c3rp-c85p): the anomalous state fails loudly in CI output rather than being silently sanitized, giving operators an opportunity to investigate whether it reflects tampering, environment contamination, or an unexpected upstream change. **2. Quote remaining metacharacters** Values containing `"` or `;`, both of which have legitimate uses (e.g., regex-valued INI settings such as `ddtrace`'s `datadog.appsec.obfuscation_parameter_value_regexp`), are wrapped in double quotes with inner `"` escaped as `\"`, so PHP's INI parser reads them as literal string contents rather than comment/delimiter tokens. Plain values are forwarded unchanged so that boolean keywords (`On`/`Off`) and bitwise expressions (`E_ALL & ~E_NOTICE`) retain their INI semantics. ## Workarounds If upgrading is not immediately possible: - Audit INI values: Ensure no `<ini value="…">` entry in `phpunit.xml` / `phpunit.xml.dist` contains newline, `"`, or `;` characters, and that nothing writes such values into configuration at build time. - Isolate CI execution of untrusted code: Run PHPUnit against pull requests only in ephemeral, containerized runners that discard filesystem state between jobs; require human review before executing PRs from forks; enforce branch protection on workflows that handle secrets (`pull_request_target` and similar). These mitigations apply to the broader PPE risk class and are effective against this vulnerability as well. - Restrict who can modify `phpunit.xml`: Treat `phpunit.xml` as security-sensitive in code review, particularly `<ini>` entries. - Sanitize host INI: Ensure the host PHP's `php.ini` does not contain values with embedded newlines or unescaped metacharacters. ## References - Fix: https://github.com/sebastianbergmann/phpunit/pull/6592 - Related advisory (same threat class, Poisoned Pipeline Execution): [GHSA-vvj3-c3rp-c85p / CVE-2026-24765](https://github.com/sebastianbergmann/phpunit/security/advisories/GHSA-vvj3-c3rp-c85p) - OWASP CI/CD Top 10: [CICD-SEC-04 Poisoned Pipeline Execution](https://owasp.org/www-project-top-10-ci-cd-security-risks/CICD-SEC-04-Poisoned-Pipeline-Execution) - CWE-88: https://cwe.mitre.org/data/definitions/88.html - CWE-93: https://cwe.mitre.org/data/definitions/93.html