CVE-2026-2555: Jeecg Boot RCE Vulnerability

CVE-2026-2555 Overview

A deserialization vulnerability has been identified in JeecgBoot version 3.9.1, affecting the Retrieval-Augmented Generation (RAG) module. This weakness exists in the importDocumentFromZip function within the file org/jeecg/modules/airag/llm/controller/AiragKnowledgeController.java. The vulnerability allows remote attackers to potentially execute arbitrary code through manipulated serialized data, though exploitation is considered highly complex and difficult to achieve.

Critical Impact

Insecure deserialization in the RAG knowledge controller could allow authenticated attackers to manipulate application behavior, potentially leading to data integrity compromise or limited information disclosure.

Affected Products

• JeecgBoot version 3.9.1
• Jeecg RAG/AI Knowledge Module (AiragKnowledgeController.java)
• Components utilizing the importDocumentFromZip functionality

Discovery Timeline

• 2026-02-16 - CVE-2026-2555 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-2555

Vulnerability Analysis

This vulnerability is classified as an Insecure Deserialization issue (CWE-502) combined with Improper Input Validation (CWE-20). The affected function importDocumentFromZip in the AiragKnowledgeController.java file does not properly validate or sanitize user-supplied input before deserializing objects from uploaded ZIP archives.

When processing ZIP file imports for the Retrieval-Augmented Generation knowledge base, the application fails to implement adequate security controls to prevent malicious serialized objects from being processed. This could allow an attacker to craft a specially prepared ZIP file containing malicious serialized data that, when processed by the application, could lead to unintended code execution or data manipulation.

The vulnerability requires network access and authenticated user privileges to exploit. The attack complexity is high, making successful exploitation difficult. Impact is limited to low confidentiality, integrity, and availability compromise within the application context.

Root Cause

The root cause of this vulnerability stems from insufficient input validation in the importDocumentFromZip function. The application processes ZIP file contents and deserializes embedded objects without proper verification of the data source or content integrity. Java deserialization vulnerabilities commonly arise when untrusted data is passed directly to deserialization functions without implementing object whitelisting or type checking mechanisms.

The absence of proper validation allows attackers to potentially inject malicious serialized objects that, when reconstructed by the Java runtime, could execute arbitrary operations within the application's security context.

Attack Vector

The attack is executed remotely over the network, targeting the document import functionality in the RAG module. An attacker would need to:

1. Authenticate to the JeecgBoot application with valid credentials
2. Access the knowledge management functionality in the AI/RAG module
3. Craft a malicious ZIP file containing specially serialized Java objects
4. Upload the malicious archive through the importDocumentFromZip endpoint
5. Trigger the deserialization of the malicious payload during document processing

The vulnerability affects the document import workflow used for populating knowledge bases in AI-assisted retrieval systems. Technical details and reproduction steps can be found in GitHub Issue #9335 and additional context is available through VulDB #346163.

Detection Methods for CVE-2026-2555

Indicators of Compromise

• Unusual ZIP file uploads to the RAG knowledge import endpoints
• Unexpected serialized object patterns in uploaded archives
• Anomalous application behavior following document import operations
• Error logs indicating deserialization failures or class loading exceptions

Detection Strategies

• Monitor HTTP requests to /airag/knowledge endpoints for suspicious file uploads
• Implement application-level logging for all deserialization operations in the RAG module
• Deploy Web Application Firewall (WAF) rules to inspect ZIP file uploads for known malicious serialization patterns
• Review application logs for ObjectInputStream errors or unexpected class instantiation attempts

Monitoring Recommendations

• Enable verbose logging for the AiragKnowledgeController component
• Configure alerting for failed deserialization attempts or unexpected object types
• Monitor file system activity in temporary directories used for ZIP extraction
• Implement network monitoring for unusual data patterns in upload requests

How to Mitigate CVE-2026-2555

Immediate Actions Required

• Review access controls for the RAG knowledge management functionality
• Restrict upload permissions to trusted administrators only
• Audit recent document imports for any suspicious activity
• Consider temporarily disabling the importDocumentFromZip functionality until a patch is available

Patch Information

As of the last update on 2026-02-18, the JeecgBoot project has been notified of this vulnerability through GitHub Issue #9335 but has not yet responded with a security patch. Organizations using JeecgBoot 3.9.1 should monitor the JeecgBoot GitHub repository for security updates and apply patches as soon as they become available.

Workarounds

• Implement application-layer input validation for all ZIP file uploads before processing
• Consider deploying a custom deserialization filter using Java's ObjectInputFilter to whitelist expected object types
• Restrict network access to the affected endpoints using firewall rules or reverse proxy configurations
• Apply the principle of least privilege to limit which users can access the document import functionality

# Configuration example: Restrict access to RAG endpoints at reverse proxy level
# Nginx configuration to limit access to knowledge import endpoints
location /jeecg-boot/airag/knowledge/ {
    # Limit to internal IP ranges only
    allow 10.0.0.0/8;
    allow 192.168.0.0/16;
    deny all;
    
    # Additional security headers
    add_header X-Content-Type-Options nosniff;
    proxy_pass http://backend;
}