CVE-2025-56236: formcms XSS — Exploit

Description

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.

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CVSS v3.1 Score

6.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
formcms	formcms	0.5.5 — 0.5.7

References

Exploits

https://github.com/FormCms/FormCms/issues/27

Other References

https://github.com/KKC73/me/blob/main/CVE-2025-56236/README.md

Frequently Asked Questions

What is CVE-2025-56236? +

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. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2025-56236? +

CVE-2025-56236 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-56236? +

CVE-2025-56236 affects products from formcms, specifically: formcms. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-56236? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2025-56236