CVE-2026-8204
Authorization Bypass in Concrete CMS Calendar Event Dialog
Publication date: 2026-05-21
Last updated on: 2026-05-21
Assigner: ConcreteCMS
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| concrete_cms | concrete_cms | to 9.5.0 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-639 | The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability in Concrete CMS 9.5.0 and below allows unauthorized access to private calendar data through a public calendar block, leading to cross-calendar data disclosure.
Such unauthorized data disclosure could potentially impact compliance with data protection regulations like GDPR and HIPAA, which require strict controls over access to personal and sensitive information.
However, the provided information does not explicitly detail the compliance implications or specific regulatory impacts of this vulnerability.
Can you explain this vulnerability to me?
This vulnerability affects Concrete CMS version 9.5.0 and below. It is an authorization bypass issue in the Calendar Event Frontend Dialog. Specifically, it allows an attacker to use a public calendar block as a pivot point to access private calendar data, leading to cross-calendar data disclosure.
How can this vulnerability impact me? :
The impact of this vulnerability is that unauthorized users can gain access to private calendar data by exploiting the authorization bypass. This could lead to exposure of sensitive or confidential information that was intended to be private.