CVE-2026-8337
Medium
Description
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
SeverityMedium
CVSS5.3
Exploit probability—
Product
Concretecms Concrete Cms
PublishedMay 21, 2026
First seenMay 21, 2026
How to fix
Update
- concretecms concrete_cms9.5.1 or later
- concrete5/concrete59.5.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| concretecms concrete_cms | v < 9.5.1 | 9.5.1 |
| concrete5/concrete5Packagist | v < 9.5.1 | 9.5.1 |
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