CVE-2026-18116

Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting.

CVSS

No CVSS.

References

Link	Resource
https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-14 23:17

Updated : 2026-09-15 14:40

NVD link : CVE-2026-18116

Mitre link : CVE-2026-18116

CVE.ORG link : CVE-2026-18116

JSON object : View

Products Affected

No product.

CWE

CWE-79

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

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