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CVE-2026-8204

5.3 MEDIUM

Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar d...

Published: 2026-05-21 · Last updated: 2026-05-26

Severity and scoring

CVSS
5.3 MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE
CWE-639

Affected products

VendorProduct
concretecmsconcrete_cms

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.

Source: NVD

References

Related CVEs

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  • CVE-2026-8340 — Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion (4.3 MEDIUM)
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  • CVE-2026-8433 — Concrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file rescan() (8.8 HIGH)
  • CVE-2026-8432 — Concrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file star() (8.8 HIGH)
  • CVE-2026-8427 — Concrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file removeFavoriteFolder(... (8.8 HIGH)

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