CVE-2026-27206
📋 TL;DR
Zumba Json Serializer versions 3.2.2 and below allow PHP Object Injection through untrusted JSON deserialization. The library's @type field can instantiate arbitrary classes, potentially leading to Remote Code Execution if dangerous magic methods exist in the application. Applications are affected only if they deserialize untrusted JSON using JsonSerializer::unserialize() and contain exploitable gadget chains.
💻 Affected Systems
- Zumba Json Serializer
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote Code Execution (RCE) through PHP Object Injection with available gadget chains, allowing complete system compromise.
Likely Case
Denial of Service or limited code execution depending on available classes and magic methods in the application.
If Mitigated
No impact if untrusted JSON is not deserialized or proper input validation is implemented.
🎯 Exploit Status
Exploitation requires finding suitable gadget chains in the application or dependencies. Similar to PHP unserialize() vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.3
Vendor Advisory: https://github.com/zumba/json-serializer/security/advisories/GHSA-v7m3-fpcr-h7m2
Restart Required: No
Instructions:
1. Update composer.json to require "zumba/json-serializer": "^3.2.3"
2. Run composer update zumba/json-serializer
3. Test application functionality after update
🔧 Temporary Workarounds
Disable @type-based object instantiation
allModify code to disable automatic object instantiation from @type field
$serializer = new \Zumba\JsonSerializer\JsonSerializer(['options' => 0]);
🧯 If You Can't Patch
- Never deserialize untrusted JSON with JsonSerializer::unserialize()
- Implement strict input validation and sanitization for all JSON input before deserialization
🔍 How to Verify
Check if Vulnerable:
Check composer.json or installed packages for zumba/json-serializer version 3.2.2 or lowerCheck Version:
composer show zumba/json-serializer | grep versionsVerify Fix Applied:
Verify installed version is 3.2.3 or higher using composer show zumba/json-serializer📡 Detection & Monitoring
Log Indicators:
- Unexpected class instantiation errors
- Unusual PHP object deserialization patterns
- Errors from magic methods like __wakeup() or __destruct()
Network Indicators:
- JSON payloads containing @type fields with unusual class names
- Requests to endpoints that accept JSON for deserialization
SIEM Query:
source="web_logs" AND (uri_path="*unserialize*" OR post_data="*@type*" OR post_data="*__wakeup*" OR post_data="*__destruct*")