GHSA-442f-wcwq-fpcf is a high-severity (CVSS 8.1) Deserialization of Untrusted Data vulnerability in yiisoft/yii. O3 Security confirms whether GHSA-442f-wcwq-fpcf is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Prevent RCE when deserializing untrusted user input
Real-World Exposure
yiisoft/yiiReal-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
Affected versions of yiisoft/yii are vulnerable to Remote Code Execution (RCE) if the application calls unserialize() on arbitrary user input.
Patches
Upgrade yiisoft/yii to version 1.1.27 or higher.
For more information
See the following links for more details:
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Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | yiisoft/yii | all versions | 1.1.27 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yiisoft/yii. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update yiisoft/yii to 1.1.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-442f-wcwq-fpcf 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.
How O3 protects you
O3 pinpoints whether GHSA-442f-wcwq-fpcf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-442f-wcwq-fpcf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-442f-wcwq-fpcf in your dependencies?
O3 detects GHSA-442f-wcwq-fpcf across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.