What is CVE-2026-3452?

CVE-2026-3452 is a high-severity vulnerability in Concrete Cms, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2026-03-04.

How severe is CVE-2026-3452?

High severity. CVSS v3 base score is 7.2 out of 10.

Deserialization in Concrete Cms

CVE-2026-3452

Concrete CMS below version 9.4.8 is vulnerable to Remote Code Execution by stored PHP object injection into the Express Entry List block via the columns parameter. An authenticated administrator can store attacker-controlled serialized data in block configuration fields that are later passed to unserialize() without class restrictions or integrity checks. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.9 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H. Thanks YJK ( @YJK0805 https://hackerone.com/yjk0805 ) of ZUSO ART https://zuso.ai/ for reporting.

Vulnerability class: Insecure Deserialization

EPSS: 0.006 (45.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Concrete Cms — versions 5
Concretecms Concrete_cms

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

ff5b8ace-8b95-4078-9743-eac1ca5451de (Broken Link)
ff5b8ace-8b95-4078-9743-eac1ca5451de (Patch, Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2026-3452?: CVE-2026-3452 is a high-severity vulnerability in Concrete Cms, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2026-03-04.
How severe is CVE-2026-3452?: High severity. CVSS v3 base score is 7.2 out of 10.