Improper Input Validation in nyholm/psr7GHSA-wjfc-pgfp-pv9c
MEDIUMGHSA-wjfc-pgfp-pv9c is a medium-severity (CVSS 5.3) vulnerability in nyholm/psr7. A fix is available for nyholm/psr7 — see the affected versions and patch details below.
Real-World Exposure
nyholm/psr7Real-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
Impact
Improper header parsing. An attacker could sneak in a newline (\n) into both the header names and values. While the specification states that \r\n\r\n is used to terminate the header list, many servers in the wild will also accept \n\n.
Patches
The issue is patched in 1.6.1.
Workarounds
There are no known workarounds.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | nyholm/psr7 | all versions | 1.6.1composer require nyholm/psr7:^1.6.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nyholm/psr7, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nyholm/psr7 to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wjfc-pgfp-pv9c 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-wjfc-pgfp-pv9c in your dependencies?
Find it across Packagist, including transitive dependencies.