CVE-2026-8347 PUBLISHED

Concrete CMS 9.5.0 and below is vulnerable to IDOR + wrong-authorization-level in Express association Reorder dialog

Assigner: ConcreteCMS
Reserved: 11.05.2026 Published: 22.05.2026 Updated: 22.05.2026

Concrete CMS 9.5.0 and below is vulnerable to IDOR + wrong-authorization-level in the Express association Reorder dialog. This can cause Cross-entity state tampering with view-only permission on one entry. To be affected, a website has to be using express and relying on express entity ordering. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 2.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	Concrete CMS
Product	Concrete CMS
Versions	Default: unaffected affected from 5.0 to 9.5.0 (incl.)

Credits

Winston Crooker finder

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes

Problem Types

CWE-639 Authorization bypass through User-Controlled key CWE

Impacts

CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs
CAPEC-122 Privilege Abuse