CVE-2026-8203

MEDIUM

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

Title source: cna
STIX 2.1

Description

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.

References (1)

Core 1

Scores

CVSS v3 5.4
EPSS 0.0012
EPSS Percentile 2.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-79
Status published
Products (2)
Concrete CMS/Concrete CMS 5 - 9.5.0
concretecms/concrete_cms < 9.5.0
Published May 21, 2026
Tracked Since May 22, 2026