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Medium severity · published May 22, 2026
CVE-2026-8347
Concrete CMS 9.5.0 and below is vulnerable to IDOR + wrong-authorization-level in Express association Reorder dialog
4.3
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CC
Concrete CMS · Concrete CMS
5.0 through 9.5.0 · source: vendor, NVD
Affected product
CC
Concrete CMS
Concrete CMS
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-8347
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-8347
Release Notes
https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
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