silverstripe/framework allows upload of dangerous file typesGHSA-vcg6-8fxc-x5cq
HIGHFix: silverstripe/silverstripe-framework@0408048GHSA-vcg6-8fxc-x5cq is a high-severity (CVSS 8.8) vulnerability in silverstripe/framework. A fix is available for silverstripe/framework — see the affected versions and patch details below.
Real-World Exposure
silverstripe/framework🐘silverstripe/framework🐘silverstripe/frameworkReal-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
Some potentially dangerous file types exist in File.allowed_extensions which could allow a malicious CMS user to upload files that then get executed in the security context of the website. We have removed the ability to upload .css, .js, .potm, .dotm, .xltm and .jar files in the default configuration. Since allowed_extensions are synced to webserver configuration (in assets/.htaccess) automatically, this will also deny access to any existing uploads with these extensions.
Review our security guidelines for the Common Web Platform and the File Security guide for SilverStripe 4 to find out how to add or remove extensions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | silverstripe/framework | ≥ 3.6.5-rc1&&< 3.6.6 | 3.6.6composer require silverstripe/framework:^3.6.6 |
| 🐘Packagist | silverstripe/framework | ≥ 4.0.3-rc1&&< 4.0.4 | 4.0.4composer require silverstripe/framework:^4.0.4 |
| 🐘Packagist | silverstripe/framework | ≥ 4.1.0-rc1&&< 4.1.1 | 4.1.1composer require silverstripe/framework:^4.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for silverstripe/framework, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update silverstripe/framework to 3.6.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vcg6-8fxc-x5cq 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-vcg6-8fxc-x5cq in your dependencies?
Find it across Packagist, including transitive dependencies.