CVE-2026-7888
HIGH EPSS 7.1%
Published Jun 3, 20263w ago · Modified Jun 17, 20261w ago
8.4 CVSS 4.0
Published Jun 3, 2026 3w ago
Last Modified Jun 17, 2026 1w ago
Description
Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction. An unauthenticated attacker may trigger arbitrary PHP object instantiation if a malicious serialized payload has been placed in the database. Thanks XananasX7 and Sanjorn Keeratirungsan (dizconnect) for both independently reporting. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.4 with vector CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Local
Attack Complexity Low
Privileges Required High
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
7.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-502 Deserialization of Untrusted Data Validation
References 1
- documentation.concretecms.org https://documentation.concretecms.org/9-x/developers/introduction/version-history/952-release-notes
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.