CVE-2026-3241

Concrete CMS below version 9.4.8 is vulnerable to a stored cross-site scripting (XSS) in the "Legacy Form" block.

Published: Mar 4, 2026Updated: Mar 4, 2026 Sources: CVE List NVD GHSACWE-79

4.8MEDIUM

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:HPrivileges Required

High

UI:RUser Interaction

Required

Scope

S:CScope

Changed

Impact

C:LConfidentiality

Low

I:LIntegrity

Low

A:NAvailability

None

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Weaknesses

CWE-79

Affected Products

concretecms

oss-projectaka concrete cms

package-ecosystem

commercialaka concrete5

Concrete CMS

Web & CMS Plugins

Exploitability

1 exploit source identified

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Official Patch Available

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Execution

Initial Access

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References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes

documentation.concretecms.org

https://github.com/concretecms/concretecms/pull/12826

github.com

https://nvd.nist.gov/vuln/detail/CVE-2026-3241

nvd.nist.gov

and 1 more references View all →

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