Concrete CMS up to 9.5.1 unserialize deserialization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.0$0-$5k2.91

Summaryinfo

A vulnerability marked as problematic has been reported in Concrete CMS up to 9.5.1. Impacted is the function unserialize. This manipulation causes deserialization. This vulnerability is tracked as CVE-2026-7888. The attack is restricted to local execution. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Concrete CMS up to 9.5.1. It has been declared as problematic. Affected by this vulnerability is the function unserialize. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was disclosed by Sanjorn Keeratirungsan. The advisory is shared at documentation.concretecms.org. This vulnerability is known as CVE-2026-7888 since 05/05/2026. The exploitation appears to be easy. An attack has to be approached locally. Additional levels of successful authentication are required for exploitation. Technical details are known, but no exploit is available.

Upgrading to version 9.5.2 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.2
VulDB Meta Temp Score: 4.0

VulDB Base Score: 4.2
VulDB Temp Score: 4.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CMS 9.5.2

Timelineinfo

05/05/2026 CVE reserved
06/03/2026 +29 days Advisory disclosed
06/03/2026 +0 days VulDB entry created
06/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: documentation.concretecms.org
Researcher: Sanjorn Keeratirungsan
Status: Confirmed

CVE: CVE-2026-7888 (🔒)
GCVE (CVE): GCVE-0-2026-7888
GCVE (VulDB): GCVE-100-368197

Entryinfo

Created: 06/03/2026 21:44
Changes: 06/03/2026 21:44 (68)
Complete: 🔍
Cache ID: 216::103

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