{"id":"CVE-2026-41570","aliases":["GHSA-qrr6-mg7r-m243"],"url":"https://o3.security/vulnerability/CVE-2026-41570","summary":"PHPUnit: Argument injection via newline in PHP INI values forwarded to child processes","details":"## Impact\n\nPHPUnit 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.\n\nAn 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.\n\nSources of INI values that participate in the attack:\n\n- `<ini name=\"…\" value=\"…\"/>` entries in `phpunit.xml` / `phpunit.xml.dist`\n- INI settings inherited from the host PHP runtime via `ini_get_all()`\n\n### Threat Model\n\nExploitation 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.\n\n### Affected component\n\n`PHPUnit\\Util\\PHP\\JobRunner::settingsToParameters()`.\n\n## Patches\n\nThe fix has two parts:\n\n**1. Reject line-break characters**\n\nBecause 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.\n\n**2. Quote remaining metacharacters**\n\nValues 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.\n\n## Workarounds\n\nIf upgrading is not immediately possible:\n\n- 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.\n- 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.\n- Restrict who can modify `phpunit.xml`: Treat `phpunit.xml` as security-sensitive in code review, particularly `<ini>` entries.\n- Sanitize host INI: Ensure the host PHP's `php.ini` does not contain values with embedded newlines or unescaped metacharacters.\n\n## References\n\n- Fix: https://github.com/sebastianbergmann/phpunit/pull/6592\n- 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)\n- 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)\n- CWE-88: https://cwe.mitre.org/data/definitions/88.html\n- CWE-93: https://cwe.mitre.org/data/definitions/93.html","published":"2026-05-08T14:33:51.630Z","modified":"2026-08-12T03:51:13.109091382Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.00191,"percentile":0.0902,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"phpunit/phpunit","fixedVersion":"12.5.22"},{"ecosystem":"Packagist","name":"phpunit/phpunit","fixedVersion":"13.1.6"}],"fix":{"url":"https://github.com/sebastianbergmann/phpunit/pull/6592","label":"sebastianbergmann/phpunit#6592"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41570.json"},{"type":"ADVISORY","url":"https://github.com/sebastianbergmann/phpunit/security/advisories/GHSA-qrr6-mg7r-m243"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41570"},{"type":"FIX","url":"https://github.com/sebastianbergmann/phpunit/pull/6592"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/phpunit/phpunit/CVE-2026-41570.yaml"},{"type":"PACKAGE","url":"https://github.com/sebastianbergmann/phpunit"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:13.109091382Z"}}