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Vulnerability Details :

CVE-2026-8205

Summary
Assigner-ConcreteCMS
Assigner Org ID-ff5b8ace-8b95-4078-9743-eac1ca5451de
Published At-21 May, 2026 | 20:57
Updated At-22 May, 2026 | 12:28
Rejected At-
Credits

Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in Calendar Block since action_get_events does not check canView on the calendar

Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in the Calendar Block since action_get_events does not check canView on the calendar which results in restricted event details being disclosed. 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 lalalala5678 for reporting.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
▼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:ConcreteCMS
Assigner Org ID:ff5b8ace-8b95-4078-9743-eac1ca5451de
Published At:21 May, 2026 | 20:57
Updated At:22 May, 2026 | 12:28
Rejected At:
▼CVE Numbering Authority (CNA)
Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in Calendar Block since action_get_events does not check canView on the calendar

Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in the Calendar Block since action_get_events does not check canView on the calendar which results in restricted event details being disclosed. 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 lalalala5678 for reporting.

Affected Products
Vendor
Concrete CMS
Product
Concrete CMS
Collection URL
https://github.com/concretecms/concretecms
Repo
https://github.com/concretecms/concretecms
Default Status
unaffected
Versions
Affected
  • From 5.0 through 9.5.0 (git)
Problem Types
TypeCWE IDDescription
CWECWE-425CWE-425 Direct request ('forced browsing')
Type: CWE
CWE ID: CWE-425
Description: CWE-425 Direct request ('forced browsing')
Metrics
VersionBase scoreBase severityVector
4.06.3MEDIUM
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
Version: 4.0
Base score: 6.3
Base severity: MEDIUM
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
Metrics Other Info
Impacts
CAPEC IDDescription
N/ACAPAC-144
CAPEC ID: N/A
Description: CAPAC-144
Solutions
Configurations
Workarounds
Exploits
Credits
finder
lalalala5678
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
release-notes
Hyperlink: https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
Resource:
release-notes
▼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
Information is not available yet
▼National Vulnerability Database (NVD)
nvd.nist.gov
Source:ff5b8ace-8b95-4078-9743-eac1ca5451de
Published At:21 May, 2026 | 21:16
Updated At:21 May, 2026 | 21:16

Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in the Calendar Block since action_get_events does not check canView on the calendar which results in restricted event details being disclosed. 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 lalalala5678 for reporting.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary4.06.3MEDIUM
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
Type: Secondary
Version: 4.0
Base score: 6.3
Base severity: MEDIUM
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/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
CPE Matches
Weaknesses
CWE IDTypeSource
CWE-425Secondaryff5b8ace-8b95-4078-9743-eac1ca5451de
CWE ID: CWE-425
Type: Secondary
Source: ff5b8ace-8b95-4078-9743-eac1ca5451de
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notesff5b8ace-8b95-4078-9743-eac1ca5451de
N/A
Hyperlink: https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
Source: ff5b8ace-8b95-4078-9743-eac1ca5451de
Resource: N/A

Change History

0
Information is not available yet

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