Concrete CMS vulnerable to Remote Code Execution by stored PHP object injection
Impact
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.
Source excerpt · OSVAffected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
| Affected range | Recorded fix |
|---|---|
| Earlier releases before 9.4.8Ecosystem versions | 9.4.8 |
Version evidence: OSV · GHSA-gj26-w59c-29mf
View original version evidence (85 explicit versions)
Original source 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 thanks YJK ( @YJK0805 https://hackerone.com/yjk0805 ) of ZUSO ART https://zuso.ai/ for reporting.
References
- Security advisory nvd.nist.gov/vuln/detail/CVE-2026-3452
- Patch github.com/concretecms/concretecms/pull/12826/changes/167f16e4805d8ab546d2997c753ac21bf4854920
- Release notes documentation.concretecms.org/9-x/developers/introduction/version-history/948-release-notes
- Source reference github.com/concretecms/concretecms