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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-45fj-fvmm-xcc5 Concrete CMS has a stored Cross-site Scripting (XSS) vulnerability
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 04 Mar 2026 21:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N'}


Wed, 04 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 04 Mar 2026 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Concretecms
Concretecms concrete Cms
Vendors & Products Concretecms
Concretecms concrete Cms

Wed, 04 Mar 2026 03:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 4.8, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: ConcreteCMS

Published:

Updated: 2026-03-04T15:33:21.842Z

Reserved: 2026-02-26T01:42:11.496Z

Link: CVE-2026-3240

cve-icon Vulnrichment

Updated: 2026-03-04T15:32:50.021Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-04T03:16:04.940

Modified: 2026-03-04T21:32:44.683

Link: CVE-2026-3240

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-04T14:53:18Z

Weaknesses