CVE-2026-8205: Concrete CMS is vulnerable to authorization bypass in the Calendar Block

medium Affects concrete5/concrete5. Feed 2026.10.29.1, updated 2026-10-28; published 2026-05-21; advisory modified 2026-09-10.

Concrete CMS is vulnerable to authorization bypass in the Calendar Block

Package: concrete5/concrete5 Composer
Affected versions: <9.5.1
Fixed in: 9.5.1
Severity: medium CVSS 5.3
Exploitation: not on CISA KEV · EPSS 0% (11.4th percentile)
Published: 2026-05-21
Source: osv.dev

References

CWE-425

NVD record concrete5/concrete5 advisories

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