Executive brief
Pimcore's Hotspotimage field (used for image annotation metadata in data objects) deserializes untrusted database columns without validating which classes can be instantiated. An attacker with database write access can inject malicious serialized PHP objects that execute arbitrary code through gadget chains when the object is loaded—for instance, during admin UI rendering or API calls. This affects multiple field types (Hotspotimage, ImageGallery, Block, Video) across all maintained versions.
Technical details
The vulnerability is a PHP Object Injection (CWE-502) in the Hotspotimage field marshaller and its siblings (ImageGallery, Block, Video). The `getDataFromResource()` method deserializes the `*__hotspots` database column via `Serialize::unserialize()`, which defaults to unrestricted class instantiation (`allowed_classes=true`). When the JSON decode fallback fails (which it does for PHP-serialized bytes), the code paths directly to `unserialize()` without a class allowlist. An attacker who can write crafted serialized bytes to the column—via SQL injection, direct database access, or other persistence layer vulnerabilities—triggers arbitrary class instantiation and magic method execution on any object load (admin grid, frontend render, API, inheritance walks). The PoC demonstrates file write via `GuzzleHttp\Cookie\FileCookieJar` gadget from bundled `guzzlehttp/guzzle 7.11.0`. The fix is to flip `Serialize::unserialize()`'s default `$allowedClasses` parameter from `true` to `false`, or pass an explicit allowlist at each call site.
Affected products
- pimcore pimcore 2026.1.0 through 2026.1.5, 12.0.0 through 12.3.9 (all currently maintained releases)
Timeline
- 2026-07-30: disclosed
- 2026-08-28: advisory
- 2026-08-28: patched: Patched in 2026.1.6 and 12.3.10