MEDIUM

GHSA-4fxf-xgrm-8fcj

FormCms avatar upload feature has a stored cross-site scripting (XSS) vulnerability

Quick fix

GHSA-4fxf-xgrm-8fcj — FormCMS: upgrade to the fixed version with the command below.

dotnet add package FormCMS --version 0.5.7

Details

FormCms v0.5.5 contains a stored cross-site scripting (XSS) vulnerability in the avatar upload feature. Authenticated users can upload .html files containing malicious JavaScript, which are accessible via a public URL. When a privileged user accesses the file, the script executes in their browser context.

Are you affected?

Enter the version of the package you're using.

Affected packages

NuGet/FormCMS

Introduced in: 0Fixed in: 0.5.7

Fixdotnet add package FormCMS --version 0.5.7

References

https://nvd.nist.gov/vuln/detail/CVE-2025-56236[ADVISORY]
https://github.com/FormCms/FormCms/issues/27[WEB]
https://github.com/KKC73/me/blob/main/CVE-2025-56236/README.md[WEB]
https://github.com/formcms/formcms[PACKAGE]