CVE-2026-24739 is a medium-severity (CVSS 6.3) CWE-88 vulnerability in symfony/process. A fix is available for symfony/process — see the affected versions and patch details below.
Symfony has incorrect argument escaping under MSYS2/Git Bash on Windows that can lead to destructive file operations
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-24739.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
symfony/process🐘symfony/process🐘symfony/process🐘symfony/process🐘symfony/process🐘symfony/symfony🐘symfony/symfony🐘symfony/symfony+2 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The Symfony Process component did not correctly treat some characters (notably =) as “special” when escaping arguments on Windows. When PHP is executed from an MSYS2-based environment (e.g. Git Bash) and Symfony Process spawns native Windows executables, MSYS2’s argument/path conversion can mishandle unquoted arguments containing these characters.
This can cause the spawned process to receive corrupted/truncated arguments compared to what Symfony intended.
Impact
If an application (or tooling such as Composer scripts) uses Symfony Process to invoke file-management commands (e.g. rmdir, del, etc.) with a path argument containing =, the MSYS2 conversion layer may alter the argument at runtime. In affected setups this can result in operations being performed on an unintended path, up to and including deletion of the contents of a broader directory or drive.
The issue is particularly relevant when untrusted input can influence process arguments (directly or indirectly, e.g. via repository paths, extracted archive paths, temporary directories, or user-controlled configuration).
Resolution
Upgrade to a Symfony release that includes the fix from symfony/symfony#63164 (which updates Windows argument escaping to ensure arguments containing = and other MSYS2-sensitive characters are properly quoted/escaped). The patch for branch 5.4 is available at https://github.com/symfony/symfony/commit/ec154f6f95f8c60f831998ec4d246a857e9d179b
Workarounds / Mitigations
Avoid running PHP/your tooling from MSYS2-based shells on Windows; prefer cmd.exe or PowerShell for workflows that spawn native executables.
Avoid passing paths containing = (and similar MSYS2-sensitive characters) to Symfony Process when operating under Git Bash/MSYS2.
Where applicable, configure MSYS2 to disable or restrict argument conversion (e.g. via MSYS2_ARG_CONV_EXCL), understanding this may affect other tooling behavior.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/process | all versions | 5.4.51composer require symfony/process:^5.4.51 |
| 🐘Packagist | symfony/process | ≥ 6.4&&< 6.4.33 | 6.4.33composer require symfony/process:^6.4.33 |
| 🐘Packagist | symfony/process | ≥ 7.3&&< 7.3.11 | 7.3.11composer require symfony/process:^7.3.11 |
| 🐘Packagist | symfony/process | ≥ 7.4&&< 7.4.5 | 7.4.5composer require symfony/process:^7.4.5 |
| 🐘Packagist | symfony/process | ≥ 8.0&&< 8.0.5 | 8.0.5composer require symfony/process:^8.0.5 |
| 🐘Packagist | symfony/symfony | all versions | 5.4.51composer require symfony/symfony:^5.4.51 |
Affected Products
symfonysensiolabsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/process, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/process to 5.4.51 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-24739 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-24739 in your dependencies?
Find it across Packagist, including transitive dependencies.