CVE-2026-8337

Concrete CMS 9.5.0 and below is vulnerable to IDOR in surveys. To be vulnerable, a site would have to be configured in such a way that both public and private surveys are present on the site. An unauthenticated attacker can vote in the restricted survey by submitting the restricted optionID through the public survey’s endpoint. 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:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Zer0daySec https://github.com/Zee99y for reporting

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

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

Configurations

Configuration 1 (hide)

cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*

History

26 May 2026, 17:13

Type	Values Removed	Values Added
CPE		cpe:2.3:a:concretecms:concrete_cms::::::::
References	~~() https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes -~~	() https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes - Release Notes
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.3
First Time		Concretecms concrete Cms Concretecms

21 May 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-21 22:16

Updated : 2026-05-26 17:13

NVD link : CVE-2026-8337

Mitre link : CVE-2026-8337

CVE.ORG link : CVE-2026-8337

JSON object : View

Products Affected

concretecms

concrete_cms

CWE

CWE-565

Reliance on Cookies without Validation and Integrity Checking

CWE-639

Authorization Bypass Through User-Controlled Key

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