High severity · published Mar 4, 2026
CVE-2026-3452
Concrete CMS below 9.4.8 is vulnerable to stored deserialization leading to RCE in the Express Entry List block.
7.2
CVSS
0.6%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 50% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CC
Concrete CMS · Concrete CMS
5 before 9.4.8 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-3452
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-3452
Patch
https://documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes
Broken Link
https://github.com/concretecms/concretecms/pull/12826/changes/167f16e4805d8ab546d2997c753ac21bf4854920://
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