CVE-2026-3452: Concrete CMS below 9.4.8 is vulnerable to stored deserialization leading to RCE in the Express Entry List block.
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 thanks YJK ( @YJK0805 https://hackerone.com/yjk0805 ) of ZUSO ART https://zuso.ai/ for reporting.
Other sources
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.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-3452?
CVE-2026-3452 is considered a high severity vulnerability due to the potential for remote code execution.
How do I fix CVE-2026-3452?
To fix CVE-2026-3452, upgrade Concrete CMS to version 9.4.8 or later.
What software is affected by CVE-2026-3452?
CVE-2026-3452 affects all versions of Concrete CMS below 9.4.8.
What type of vulnerability is CVE-2026-3452?
CVE-2026-3452 is a stored deserialization vulnerability leading to remote code execution.
Who can exploit CVE-2026-3452?
An authenticated administrator can exploit CVE-2026-3452 through PHP object injection.