Vulnerability Description
Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot point to access private calendar data. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-8204?
CVE-2026-8204 is a documented vulnerability. Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot ...
How severe is CVE-2026-8204?
CVSS scoring is not yet available for CVE-2026-8204. Check NVD for updates.
Is there a patch for CVE-2026-8204?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.