What is CVE-2026-8337?

CVE-2026-8337 is a medium-severity vulnerability in Concrete Cms, classified under Reliance on Cookies without Validation and Integrity Checking. CVSS score: 5.3/10. Published 2026-05-21.

How severe is CVE-2026-8337?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in Concrete Cms

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 res…

EPSS: 0.001 (18.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Concrete Cms — versions 5.0
Concretecms Concrete_cms

Weakness classification (CWE)

CWE-565 — Reliance on Cookies without Validation and Integrity Checking
CWE-639 — Authorization Bypass Through User-Controlled Key

References

ff5b8ace-8b95-4078-9743-eac1ca5451de (release-notes, Release Notes)

Frequently asked questions

What is CVE-2026-8337?: CVE-2026-8337 is a medium-severity vulnerability in Concrete Cms, classified under Reliance on Cookies without Validation and Integrity Checking. CVSS score: 5.3/10. Published 2026-05-21.
How severe is CVE-2026-8337?: Medium severity. CVSS v3 base score is 5.3 out of 10.