Summary
silverstripe/framework allows upload of dangerous file types
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.
Impact
The application accepts file uploads without adequately restricting the file type or content. Typical impact: remote code execution if the uploaded file can be served and executed on the server.
GHSA-VCG6-8FXC-X5CQ has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.6.6, 4.0.4, 4.1.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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silverstripe/framework to 3.6.6 or later; silverstripe/framework to 4.0.4 or later; silverstripe/framework to 4.1.1 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-VCG6-8FXC-X5CQ? GHSA-VCG6-8FXC-X5CQ is a high-severity unrestricted upload of dangerous file types vulnerability in silverstripe/framework (composer), affecting versions >= 3.6.5-rc1, < 3.6.6. It is fixed in 3.6.6, 4.0.4, 4.1.1. The application accepts file uploads without adequately restricting the file type or content.
- How severe is GHSA-VCG6-8FXC-X5CQ? GHSA-VCG6-8FXC-X5CQ has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of silverstripe/framework are affected by GHSA-VCG6-8FXC-X5CQ? silverstripe/framework (composer) versions >= 3.6.5-rc1, < 3.6.6 is affected.
- Is there a fix for GHSA-VCG6-8FXC-X5CQ? Yes. GHSA-VCG6-8FXC-X5CQ is fixed in 3.6.6, 4.0.4, 4.1.1. Upgrade to this version or later.
- Is GHSA-VCG6-8FXC-X5CQ exploitable, and should I be worried? Whether GHSA-VCG6-8FXC-X5CQ is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-VCG6-8FXC-X5CQ is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-VCG6-8FXC-X5CQ?
- Upgrade
silverstripe/frameworkto 3.6.6 or later - Upgrade
silverstripe/frameworkto 4.0.4 or later - Upgrade
silverstripe/frameworkto 4.1.1 or later
- Upgrade