SecuriTricks - CVE-2026-7888

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.

Product(s) Impacted

Vendor	Product	Versions
Concrete	Concrete Cms	<9.5.2

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-502

Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	concrete	concrete_cms	<9.5.2	/	/	/	/	/	/	/

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/952-release-notes

CVSS Score

8.4 / 10

CVSS Data - 4.0

Attack Vector: LOCAL
Attack Complexity: LOW
Attack Requirements: NONE
Privileges Required: HIGH
User Interaction: NONE
Scope:
Confidentiality Impact: HIGH
Integrity Impact: HIGH
Availability Impact: HIGH
Exploit Maturity: NOT_DEFINED

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

View Vector String

Timeline

Published: June 3, 2026, 7:16 p.m.
Last Modified: June 4, 2026, 3:20 p.m.

Status : Deferred

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

ff5b8ace-8b95-4078-9743-eac1ca5451de

CVE-2026-7888