Concrete CMS below 9.5.3 is vulnerable to PHP Object Injection via unserialize()
calls in the Workflow, Form block, and File/Set components that lack the
allowed_classes restriction. The Form block and File/Set sinks were addressed in
9.5.2; the Workflow component sinks were addressed in 9.5.3. 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 independently reporting the original components, and sh4d0byss for
reporting the Workflow component wasn't fixed in 9.5.2. 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.
Metrics
Affected Vendors & Products
References
History
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | Concrete CMS below 9.5.3 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction. The Form block and File/Set sinks were addressed in 9.5.2; the Workflow component sinks were addressed in 9.5.3. 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 independently reporting the original components, and sh4d0byss for reporting the Workflow component wasn't fixed in 9.5.2. 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. |
| Title | 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. | Concrete CMS below 9.5.3 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction. |
Wed, 03 Jun 2026 22:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Concretecms
Concretecms concrete Cms |
|
| Vendors & Products |
Concretecms
Concretecms concrete Cms |
Wed, 03 Jun 2026 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 03 Jun 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | 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. | |
| Weaknesses | CWE-502 | |
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: ConcreteCMS
Published: 2026-06-03T18:10:10.917Z
Updated: 2026-09-11T19:04:23.786Z
Reserved: 2026-05-05T20:23:08.863Z
Link: CVE-2026-7888
Updated: 2026-06-03T19:07:52.022Z
Status : Deferred
Published: 2026-06-03T19:16:38.910
Modified: 2026-09-11T20:18:54.320
Link: CVE-2026-7888
No data.