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7.8
PHPUnit allows malicious PHP settings to be injected in test runs
GHSA-qrr6-mg7r-m243
Summary
Attackers can influence PHP settings used in PHPUnit test runs, potentially allowing them to execute arbitrary code. This can happen if an attacker has write access to the project's phpunit.xml file or the host PHP configuration. To prevent this, ensure that only trusted users can modify PHPUnit configuration files and PHP settings.
What to do
- Update phpunit phpunit to version 12.5.22.
- Update phpunit phpunit to version 13.1.6.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| composer | phpunit | phpunit |
<= 12.5.21 >= 13.0.0, <= 13.1.5 Fix: upgrade to 12.5.22
|
Original title
PHPUnit has Argument injection via newline in PHP INI values that are forwarded to child processes
Original description
## 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
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
ghsa CVSS3.1
7.8
Vulnerability type
CWE-88
CWE-93
Published: 18 Apr 2026 · Updated: 18 Apr 2026 · First seen: 18 Apr 2026