GHSA-36fc-7wjg-mfvj is a high-severity (CVSS 8) Deserialization of Untrusted Data vulnerability in pimcore/pimcore. O3 Security confirms whether GHSA-36fc-7wjg-mfvj is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Pimcore has Unsafe PHP Deserialization in Multiple Locations Without allowed_classes Restriction
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-36fc-7wjg-mfvj.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-36fc-7wjg-mfvj plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pimcore/pimcore🐘pimcore/pimcore🐘pimcore/pimcoreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
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/pimcoreandpimcore/admin-ui-classic-bundle - Files:
lib/Tool/Authentication.php(line 82) — session token deserializationmodels/Site/Dao.php(line 68) — site domains from databasemodels/DataObject/ClassDefinition/CustomLayout/Dao.php(line 69) — layout definitions from databasemodels/Tool/TmpStore/Dao.php(line 64) — temporary store data from databasemodels/Asset/WebDAV/Service.php(line 36) — delete log from filesystemadmin-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
- Identify a writable data source (e.g.,
tmp_storetable via SQL injection, orwebdav-delete.datvia file write) - Write a serialized PHP gadget chain (e.g., Monolog
BufferHandlerchain from phpggc) - Trigger the deserialization (e.g., access a page that reads TmpStore, or trigger a WebDAV operation)
- 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.
// 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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | pimcore/pimcore | ≥ 12.0.0-RC1&&< 12.3.7 | 12.3.7 |
| 🐘Packagist | pimcore/pimcore | all versions | 11.5.17 |
| 🐘Packagist | pimcore/pimcore | ≥ 2026.1.0&&< 2026.1.3 | 2026.1.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pimcore/pimcore. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update pimcore/pimcore to 12.3.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-36fc-7wjg-mfvj is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-36fc-7wjg-mfvj is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-36fc-7wjg-mfvj. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-36fc-7wjg-mfvj in your dependencies?
O3 detects GHSA-36fc-7wjg-mfvj across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.