CVE-2026-3240

In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. 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 minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security 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
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 4.8
First Time		Concretecms concrete Cms Concretecms
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
CPE		cpe:2.3:a:concretecms:concrete_cms::::::::

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-2026-3240

Mitre link : CVE-2026-3240

CVE.ORG link : CVE-2026-3240

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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