XSS in Formcms

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-56236: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-56236?
CVE-2025-56236 is a medium-severity vulnerability in Formcms, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-08-28.
How severe is CVE-2025-56236?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2025-56236 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.