CVE-2026-8347

🔶 medium

Summary

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 Score

4.3

Medium

EPSS Score

0.0

Exploit Probability

Published Date

2026-05-22

First Seen: 2026-05-27

📊 Relative Risk Intelligence

This CVE is Lower Risk - more severe than 5.4% of all 328,009 vulnerabilities in our database.

#310,261

Below average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: May 22, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

Winston Crooker

SSVC data provided by CISA

Last Modified 2026-05-22

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS Vector 4.0

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CWE IDs (Weakness Types)

CWE-639

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
concretecms	concrete_cms	Affected	< 9.5.1

🔗 References 1

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-8340	🔶 medium	4.3	0.0	Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion. Victim with edit_file_contents p...	2026-05-22
CVE-2026-8353	🔶 medium	4.8	0.0	Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme. A rogue editor can inj...	2026-05-22
CVE-2026-6826	🔶 medium	5.3	0.0	Concrete CMS 9.5.0 and below is vulnerable to unauthenticated file usage disclosure via missing permission check in t...	2026-05-21
CVE-2026-8134	⚠️ high	7.2	0.5	Concrete CMS 9.5.0 and below fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTempl...	2026-05-21
CVE-2026-8135	⚠️ high	7.2	0.2	Concrete CMS 9.5.0 and below is vulnerable to Remote Code Execution due to insecure deserialization occurring in the E...	2026-05-21
CVE-2026-8140	🔶 medium	6.5	0.0	Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/install/down...	2026-05-21

These CVEs affect the same products