CVE-2026-8203 PUBLISHED

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

Assigner: ConcreteCMS
Reserved: 09.05.2026 Published: 21.05.2026 Updated: 22.05.2026

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.

Metrics

CVSS 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
CVSS Score: 7.3

Product Status

Vendor Concrete CMS
Product Concrete CMS
Versions Default: unaffected
  • affected from 5 to 9.5.0 (incl.)

Credits

  • Alfin Joseph finder

References

Problem Types

  • CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') CWE

Impacts

  • CAPEC-198 XSS Targeting Error Pages