CVE-2026-3240

UNKNOWN 0.0

Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	concrete cms
Product	concrete cms
Published	Mar 4, 2026
Last Updated	Mar 4, 2026

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Affected Versions

Concrete CMS / Concrete CMS

5 < 9.4.8

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/concretecms/concretecms/pull/12826 documentation.concretecms.org: https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes

Credits

minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security