CVE-2026-8204
MEDIUM EPSS 11.4%
Published May 21, 20261mo ago · Modified Jun 17, 20262w ago
6.3 CVSS 4.0
Published May 21, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
11.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-639
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| concretecms | concrete_cms | * | <9.5.1 |
References 1
- documentation.concretecms.org https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.