🛡️ CVE-2026-8204
🟡 CVSS 5.3 — Medium ✅ No Known Exploit CWE-639 NVD
5.3
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Details

Severity MEDIUM
CVSS Score 5.3
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE CWE-639
Public Exploit ✅ No
Source NVD
Published 2026-05-21
Updated 2026-06-02
Modified 2026-05-26
Fix URL N/A

Affected Packages

Software From version Fixed in
concrete-cms 9.5.1
unknown

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