Executive brief
Pimcore is an open-source platform used by businesses to manage digital data and customer experiences. A security vulnerability exists where the system improperly processes certain data stored in its database or files. If an attacker manages to modify this stored data, they could potentially take full control of the server, leading to data theft or service disruption.
Technical details
A PHP object injection vulnerability exists in multiple Pimcore components, including the Authentication tool, Site DAO, and WebDAV service. The root cause is the use of the native PHP unserialize() function on data retrieved from database columns and the filesystem without specifying the 'allowed_classes' restriction. While an attacker typically needs a secondary vulnerability (like SQL injection or file write) to control the serialized data source, successful exploitation allows them to leverage existing gadget chains (e.g., Guzzle, Monolog) to achieve remote code execution. The issue is fixed in versions 11.5.17 (LTS) and 12.3.7 by hardening the unserializer and refining allowed classes.
Affected products
- Pimcore Pimcore < 11.5.17, >= 12.0.0, < 12.3.7
Timeline
- 2026-05-08: patched: Fix merged into version 12.3 branch
- 2026-05-19: advisory: Release 12.3.7 published
- 2026-05-26: disclosed: GitHub Security Advisory published
- 2026-07-17: disclosed: CVE published to NVD