CVE-2026-45162: Multiple Locations Without allowed_classes Restriction · Pimcore Has Unsafe PHP Deserialization
Affects pimcore/pimcoreSource GCVE Database
Not known to be exploited · CVSS 8.0 High : upgrade to 12.3.7 soon.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.9% chance of exploitation in 30 days – higher than 62% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 12.3.7, 11.5.17, 2026.1.3
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade pimcore/pimcore to 12.3.7; pimcore/pimcore to 11.5.17; pimcore/pimcore to 2026.1.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Packagistpimcore/pimcore | Affected
| Fixed in
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| Packagistpimcore/pimcore | Affected
| Fixed in
|
| Packagistpimcore/pimcore | Affected
| Fixed in
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Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The advisory suggests adding the allowed_classes parameter to all unserialize() calls to restrict object instantiation, e.g., using ['allowed_classes' => false] when no objects are needed. Alternatively, migrating serialization to JSON for data that does not require object preservation is recommended. If you cannot patch yet, review and harden access controls to prevent unauthorized writes to the affected data sources (database tables and filesystem files).
Description
# GitHub Security Advisory Draft — GM-374 ## Summary Multiple locations in Pimcore v11 call PHP's `unserialize()` on data from database columns and filesystem files without the `allowed_classes` restriction, enabling object injection if an attacker can control the serialized data source. ## Severity CVSS 3.1: 8.0 (High) — AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H ## Affected Component - **Package:** `pimcore/pimcore` and `pimcore/admin-ui-classic-bundle` - **Files:** - `lib/Tool/Authentication.php` (line 82) — session token deserialization - `models/Site/Dao.php` (line 68) — site domains from database - `models/DataObject/ClassDefinition/CustomLayout/Dao.php` (line 69) — layout definitions from database - `models/Tool/TmpStore/Dao.php` (line 64) — temporary store data from database - `models/Asset/WebDAV/Service.php` (line 36) — delete log from filesystem - `admin-ui-classic-bundle/src/Helper/Dashboard.php` (line 64) — dashboard config from filesystem ## Description Six locations in Pimcore core call `unserialize()` directly (bypassing `Tool\Serialize`) on data sourced from database columns or filesystem files without passing the `allowed_classes` parameter. This means any class available in the autoloader will be instantiated during deserialization. If an attacker can write to the data source (e.g., via SQL injection targeting the `tmp_store`, `sites`, or `custom_layouts` tables, or via a file write vulnerability targeting the WebDAV delete log), they can inject serialized PHP gadget chains that execute arbitrary code when the data is deserialized. This is related to but distinct from the `Tool\Serialize::unserialize()` issue — these calls bypass the wrapper entirely. ## Impact PHP object injection leading to Remote Code Execution when chained with a data source write vulnerability. Pimcore's dependency tree (Guzzle, Symfony, Monolog, Doctrine) provides numerous known gadget chains. ## Proof of Concept 1. Identify a writable data source (e.g., `tmp_store` table via SQL injection, or `webdav-delete.dat` via file write) 2. Write a serialized PHP gadget chain (e.g., Monolog `BufferHandler` chain from phpggc) 3. Trigger the deserialization (e.g., access a page that reads TmpStore, or trigger a WebDAV operation) 4. The gadget chain executes with web server privileges ## Suggested Fix Add `allowed_classes` parameter to all `unserialize()` calls. Where no objects are needed, use `['allowed_classes' => false]`. Consider migrating to JSON serialization for data that doesn't require object preservation. ```php // Example fix for Site/Dao.php: $siteDomains = unserialize($site['domains'], ['allowed_classes' => false]); // Example fix for TmpStore/Dao.php: $item['data'] = unserialize($item['data'], ['allowed_classes' => false]); ``` ## References - CWE-502: Deserialization of Untrusted Data - OWASP Deserialization Cheat Sheet - phpggc: PHP Generic Gadget Chains
References
- github.com/pimcore/pimcore/security/advisories/GHSA-36fc-7wjg-mfvj (opens in a new tab)
- github.com/pimcore/pimcore/pull/19119 (opens in a new tab)
- github.com/pimcore/pimcore/commit/4788bf3a3a7f2f760a8fe61e522565941e154e1e (opens in a new tab)
- github.com/pimcore/pimcore (opens in a new tab)
- github.com/pimcore/pimcore/releases/tag/v12.3.7 (opens in a new tab)