CVE-2026-8203CWE-79

Concrete CMS 9.5.0 and below has Stored XSS on the height parameter

High · published May 21, 2026

CVSS v4.0
7.3
EPSS
0%
Percentile
10.2
In the wild
Unconfirmed
What it is

Concrete CMS 9.5.0 and below has Stored XSS on the height parameter. The controller does not validate or sanitize $height. Any user with editor privileges can inject malicious JavaScript that executes in the context of any visitor's browser, potentially leading to session hijacking, credential theft, or other malicious actions. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Alfin Joseph for reporting.

The record
Technical detail
CVSS v4.0
7.3 · HIGH
Vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.00207 · 10.2th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-05-21T20:31Z
EPSS history
Timeline
  • 21 MAY 20:31Z
    Concrete CMS 9.5.0 and below has Stored XSS on the height parameter
    cvelistv5