CVE Catalog

CVE-2025-56236

MediumCVSS 6.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

10th percentile - higher than 10% of all known CVEs

Summary

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.

Risk Assessment

The malicious script can execute in a privileged user's session, enabling credential theft or actions performed on their behalf. This can lead to privilege escalation and system compromise.

Recommendation

Update FormCms to a version where the vulnerability is fixed, or restrict the ability to upload .html files as avatars. Implement file type and content validation and serve uploaded files with a Content-Disposition: attachment header.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS