Symfony allows internal address and port enumeration by NoPrivateNetworkHttpClientGHSA-9c3x-r3wp-mgxm
LOWFix: symfony/symfony@296d4b3GHSA-9c3x-r3wp-mgxm is a low-severity (CVSS 3.1) Information Exposure vulnerability in symfony/http-client. A fix is available for symfony/http-client — 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-9c3x-r3wp-mgxm.
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/http-client🐘symfony/http-client🐘symfony/http-client🐘symfony/symfony🐘symfony/symfony🐘symfony/symfonyReal-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
When using the NoPrivateNetworkHttpClient, some internal information is still leaking during host resolution, which leads to possible IP/port enumeration.
Resolution
The NoPrivateNetworkHttpClient now filters blocked IPs earlier to prevent such leaks.
The fisrt patch for this issue is available here for branch 5.4.
The second one is available here for branch 5.4 also.
Credits
We would like to thank Linus Karlsson and Chris Smith for reporting the issue and Nicolas Grekas for providing the fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/http-client | ≥ 4.3.0&&< 5.4.47 | 5.4.47composer require symfony/http-client:^5.4.47 |
| 🐘Packagist | symfony/http-client | ≥ 6.0.0&&< 6.4.15 | 6.4.15composer require symfony/http-client:^6.4.15 |
| 🐘Packagist | symfony/http-client | ≥ 7.0.0&&< 7.1.8 | 7.1.8composer require symfony/http-client:^7.1.8 |
| 🐘Packagist | symfony/symfony | ≥ 4.3.0&&< 5.4.47 | 5.4.47composer require symfony/symfony:^5.4.47 |
| 🐘Packagist | symfony/symfony | ≥ 6.0.0&&< 6.4.15 | 6.4.15composer require symfony/symfony:^6.4.15 |
| 🐘Packagist | symfony/symfony | ≥ 7.0.0&&< 7.1.8 | 7.1.8composer require symfony/symfony:^7.1.8 |
Affected Products
httpclientsensiolabsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/http-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/http-client to 5.4.47 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9c3x-r3wp-mgxm is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is GHSA-9c3x-r3wp-mgxm in your dependencies?
Find it across Packagist, including transitive dependencies.