CVE-2026-4230: Vanna-AI Vanna SQL Injection Vulnerability

CVE-2026-4230 Overview

A SQL injection vulnerability has been discovered in vanna-ai vanna up to version 2.0.2. The vulnerability affects the update_sql function located in the file src/vanna/legacy/flask/__init__.py within the Endpoint component. This flaw allows attackers to inject malicious SQL commands, potentially leading to unauthorized data access, modification, or deletion. The attack can be launched remotely, and proof-of-concept exploit code has been publicly disclosed. The vendor was contacted about this vulnerability but did not respond.

Critical Impact

Remote attackers can exploit the SQL injection vulnerability in the update_sql function to manipulate database queries, potentially accessing or modifying sensitive data stored in backend databases.

Affected Products

• vanna-ai vanna versions up to 2.0.2
• Flask-based deployments using the legacy endpoint component

Discovery Timeline

• 2026-03-16 - CVE CVE-2026-4230 published to NVD
• 2026-03-16 - Last updated in NVD database

Technical Details for CVE-2026-4230

Vulnerability Analysis

This vulnerability is classified as CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), commonly manifesting as SQL injection. The update_sql function in the legacy Flask endpoint fails to properly sanitize user-supplied input before incorporating it into SQL queries. This allows remote authenticated attackers with low privileges to inject arbitrary SQL commands that are executed by the database backend.

The vulnerability exists in the Flask-based web interface component of the vanna-ai application, which is designed to assist with SQL query generation. The irony of a SQL-focused AI tool containing a SQL injection vulnerability underscores the importance of input validation in all user-facing endpoints.

Root Cause

The root cause of this vulnerability is improper input validation and lack of parameterized queries in the update_sql function within src/vanna/legacy/flask/__init__.py. User-controlled data is directly concatenated or interpolated into SQL statements without proper sanitization or the use of prepared statements. This allows specially crafted input to break out of the intended SQL context and execute attacker-controlled commands.

Attack Vector

The attack can be launched remotely over the network. An attacker requires low-level privileges (authenticated access) to exploit this vulnerability. No user interaction is required for successful exploitation. The attacker sends a malicious request to the vulnerable update_sql endpoint containing SQL injection payloads. These payloads are processed without proper sanitization and executed against the backend database.

The vulnerability has a public proof-of-concept available, which demonstrates the injection technique. Technical details can be found in the GitHub Gist PoC published by security researcher YLChen-007.

Detection Methods for CVE-2026-4230

Indicators of Compromise

• Unusual SQL error messages in application logs originating from the /update_sql endpoint
• Database query logs showing unexpected SQL commands such as UNION SELECT, DROP TABLE, or '; -- patterns
• Anomalous database access patterns or unauthorized data modifications
• Web server logs showing requests to the legacy Flask endpoint with suspicious parameters containing SQL syntax

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common SQL injection patterns in HTTP requests
• Implement database activity monitoring to identify anomalous queries originating from the vanna application
• Configure SentinelOne Singularity to monitor for process behaviors consistent with SQL injection exploitation
• Review application logs for error messages indicating failed SQL injection attempts

Monitoring Recommendations

• Enable detailed logging on the Flask application to capture all requests to the update_sql endpoint
• Configure database audit logging to track all queries executed by the vanna application user
• Set up alerting for SQL syntax errors or injection-related exception patterns in application logs
• Monitor network traffic for unusual data exfiltration patterns from database servers

How to Mitigate CVE-2026-4230

Immediate Actions Required

• Upgrade vanna-ai vanna to a version newer than 2.0.2 when a patched version becomes available
• Restrict network access to the vulnerable Flask endpoint using firewall rules or network segmentation
• Implement input validation and WAF rules to block SQL injection payloads targeting the /update_sql endpoint
• Review and audit database permissions to minimize the impact of potential SQL injection attacks

Patch Information

At the time of publication, the vendor (vanna-ai) has not responded to disclosure communications regarding this vulnerability. Users should monitor the official vanna-ai GitHub repository for security updates. Additional vulnerability details are available through VulDB #351153.

Workarounds

• Disable or restrict access to the legacy Flask endpoint (src/vanna/legacy/flask/__init__.py) if not required for operations
• Implement a reverse proxy with SQL injection filtering in front of the vanna application
• Use database-level prepared statements by modifying the update_sql function to use parameterized queries
• Apply the principle of least privilege to database accounts used by the vanna application to limit potential damage

# Example: Restrict access to the vulnerable endpoint using iptables
# Only allow access from trusted internal networks
iptables -A INPUT -p tcp --dport 5000 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 5000 -j DROP