Symfony has an incorrect response from Validator when input ends with `\n`GHSA-g3rh-rrhp-jhh9
LOWFix: symfony/symfony@7d1032bGHSA-g3rh-rrhp-jhh9 is a low-severity (CVSS 3.1) Improper Input Validation vulnerability in symfony/symfony. A fix is available for symfony/symfony — see the affected versions and patch details below.
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 GHSA-g3rh-rrhp-jhh9.
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/symfony🐘symfony/symfony🐘symfony/symfony🐘symfony/validator🐘symfony/validator🐘symfony/validatorReal-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
Description
It is possible to trick a Validator configured with a regular expression using the $ metacharacters, with an input ending with \n.
Resolution
Symfony now uses the D regex modifier to match the entire input.
The patch for this issue is available here for branch 5.4.
Credits
We would like to thank Offscript for reporting the issue and Alexandre Daubois for providing the fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/symfony | all versions | 5.4.43composer require symfony/symfony:^5.4.43 |
| 🐘Packagist | symfony/symfony | ≥ 6.0.0&&< 6.4.11 | 6.4.11composer require symfony/symfony:^6.4.11 |
| 🐘Packagist | symfony/symfony | ≥ 7.0.0&&< 7.1.4 | 7.1.4composer require symfony/symfony:^7.1.4 |
| 🐘Packagist | symfony/validator | all versions | 5.4.43composer require symfony/validator:^5.4.43 |
| 🐘Packagist | symfony/validator | ≥ 6.0.0&&< 6.4.11 | 6.4.11composer require symfony/validator:^6.4.11 |
| 🐘Packagist | symfony/validator | ≥ 7.0.0&&< 7.1.4 | 7.1.4composer require symfony/validator:^7.1.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/symfony, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/symfony to 5.4.43 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g3rh-rrhp-jhh9 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 GHSA-g3rh-rrhp-jhh9 in your dependencies?
Find it across Packagist, including transitive dependencies.