CVE-2026-3241

In Concrete CMS below version 9.4.8, a stored cross-site scripting (XSS) vulnerability exists in the "Legacy Form" block. An authenticated user with permissions to create or edit forms (e.g., a rogue administrator) can inject a persistent JavaScript payload into the options of a multiple-choice question (Checkbox List, Radio Buttons, or Select Box). This payload is then executed in the browser of any user who views the page containing the form. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks M3dium for reporting.

CVSS v3 4.8 MEDIUM

4.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.7 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes	Release Notes Patch Vendor Advisory
https://github.com/concretecms/concretecms/pull/12826	Exploit Issue Tracking Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*

History

04 Mar 2026, 21:32

Type	Values Removed	Values Added
References	~~() https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes -~~	() https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes - Release Notes, Patch, Vendor Advisory
References	~~() https://github.com/concretecms/concretecms/pull/12826 -~~	() https://github.com/concretecms/concretecms/pull/12826 - Exploit, Issue Tracking, Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 4.8
CPE		cpe:2.3:a:concretecms:concrete_cms::::::::
First Time		Concretecms concrete Cms Concretecms

04 Mar 2026, 03:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-04 03:16

Updated : 2026-03-04 21:32

NVD link : CVE-2026-3241

Mitre link : CVE-2026-3241

CVE.ORG link : CVE-2026-3241

JSON object : View

Products Affected

concretecms

concrete_cms

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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