What is CVE-2021-28935?

CVE-2021-28935 is a medium-severity vulnerability in Cmsmadesimple Cms Made Simple, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-03-30.

How severe is CVE-2021-28935?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Is CVE-2021-28935 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Cmsmadesimple Cms Made Simple

CVE-2021-28935

CMS Made Simple (CMSMS) 2.2.15 allows authenticated XSS via the /admin/addbookmark.php script through the Site Admin > My Preferences > Title field.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-03-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.016 (74.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Cmsmadesimple Cms Made Simple — versions 2.2.15

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

dev.cmsmadesimple.org/bug/view/12432 (Exploit, Issue Tracking, Vendor Advisory)
packetstormsecurity.com/files/162287/CMS-Made-Simple-2.2.15-Cross-Site-Scriptin… (Exploit, VDB Entry, Third Party Advisory)

Frequently asked questions

What is CVE-2021-28935?: CVE-2021-28935 is a medium-severity vulnerability in Cmsmadesimple Cms Made Simple, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-03-30.
How severe is CVE-2021-28935?: Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2021-28935 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.