GitHub Advisoryadvisory · Packagist

GHSA-x2fp-hj8c-mmxh Concrete CMS is vulnerable to authorization bypass in the Calendar Event Frontend Dialog

MEDIUM Published 2026-05-21 Modified 2026-06-24 Official page ↗
Aliases
CVE-2026-8204
Ecosystem
Packagist
Packages
concrete5/concrete5
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weaknesses
CWE-639
Reviewed
2026-06-24

Affected packages

• Packagist concrete5/concrete5: < 9.5.1 → fixed in 9.5.1

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.

Related

Alias · CVE (1)

  • CVE-2026-8204 Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar… vulnerability

Weakness · CWE (1)

  • CWE-639 Authorization Bypass Through User-Controlled Key weakness

References