CVE-2026-23984: Apache Superset Auth Bypass Vulnerability

CVE-2026-23984 Overview

An Improper Input Validation vulnerability exists in Apache Superset that allows an authenticated user with SQLLab access to bypass the read-only verification check when using a PostgreSQL database connection. While the system effectively blocks standard Data Manipulation Language (DML) statements (e.g., INSERT, UPDATE, DELETE) on read-only connections, it fails to detect them in specially crafted SQL statements.

This authorization bypass vulnerability affects the SQLLab component's query validation mechanism, potentially allowing unauthorized data modification operations against PostgreSQL databases that should be protected by read-only access controls.

Critical Impact

Authenticated users with SQLLab access can bypass read-only protections and execute unauthorized DML operations against PostgreSQL databases, potentially leading to data integrity compromise.

Affected Products

• Apache Superset versions before 6.0.0
• Apache Superset installations using PostgreSQL database connections
• Apache Superset environments with SQLLab enabled

Discovery Timeline

• 2026-02-24 - CVE-2026-23984 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-23984

Vulnerability Analysis

This vulnerability stems from improper input validation in Apache Superset's SQLLab feature, specifically in how the application validates SQL queries against read-only database connections. The read-only enforcement mechanism uses pattern matching or keyword detection to identify and block DML statements such as INSERT, UPDATE, and DELETE. However, the validation logic can be circumvented through specially crafted SQL statements that obfuscate these keywords while remaining syntactically valid for PostgreSQL execution.

The vulnerability is classified under CWE-863 (Incorrect Authorization), as the application fails to properly enforce access controls that should prevent data modification operations on read-only connections. An authenticated attacker with legitimate SQLLab access can exploit this flaw to perform unauthorized write operations, potentially compromising data integrity across connected PostgreSQL databases.

Root Cause

The root cause lies in insufficient SQL parsing and validation within the read-only connection enforcement logic. The application relies on basic pattern matching to detect prohibited DML statements rather than implementing comprehensive SQL parsing that would catch obfuscated or encoded variations of these commands. This allows attackers to craft SQL statements that bypass the keyword detection while still being interpreted correctly by the PostgreSQL database engine.

Attack Vector

The attack requires network access and valid authentication credentials with SQLLab privileges. An attacker would craft malicious SQL queries designed to evade the read-only detection mechanism while containing executable DML operations. Since the vulnerability affects the input validation layer, the attacker can leverage various SQL syntax techniques specific to PostgreSQL to obfuscate their queries.

The attack flow involves:

1. Authenticating to Apache Superset with SQLLab access
2. Connecting to a PostgreSQL database configured as read-only
3. Crafting SQL statements that bypass the DML detection logic
4. Executing unauthorized data modification operations

Since no verified code examples are available, technical details regarding specific bypass techniques can be found in the Apache Security Mailing List Thread and Openwall OSS Security Discussion.

Detection Methods for CVE-2026-23984

Indicators of Compromise

• Unusual DML operations appearing in PostgreSQL database logs from connections that should be read-only
• SQLLab query history containing obfuscated or encoded SQL statements
• Unexpected data modifications in databases connected through read-only Superset connections
• Database audit logs showing write operations from Superset application accounts configured for read-only access

Detection Strategies

• Monitor PostgreSQL database logs for write operations originating from Superset application connections configured as read-only
• Implement database-level auditing to track all DML operations independent of application-layer controls
• Review SQLLab query logs for suspicious patterns or obfuscated SQL syntax
• Deploy network monitoring to detect anomalous database traffic patterns from Superset instances

Monitoring Recommendations

• Enable comprehensive query logging in PostgreSQL for all Superset database connections
• Configure alerts for any write operations detected on databases designated as read-only in Superset
• Implement regular audits of SQLLab user activities and query histories
• Deploy SentinelOne Singularity XDR to monitor for suspicious application behavior and potential exploitation attempts

How to Mitigate CVE-2026-23984

Immediate Actions Required

• Upgrade Apache Superset to version 6.0.0 or later immediately
• Review and audit recent SQLLab query activity for potential unauthorized data modifications
• Implement database-level read-only user permissions as a defense-in-depth measure
• Restrict SQLLab access to only essential users until patching is complete

Patch Information

Users are recommended to upgrade to Apache Superset version 6.0.0, which fixes this vulnerability. The patch addresses the input validation weakness in the SQLLab read-only connection enforcement mechanism.

For detailed patch information and upgrade instructions, refer to the Apache Security Mailing List Thread.

Workarounds

• Configure PostgreSQL database users with actual read-only permissions at the database level rather than relying solely on Superset's application-level controls
• Temporarily disable SQLLab access for non-essential users until the upgrade is applied
• Implement network segmentation to limit database access from Superset instances
• Enable PostgreSQL's built-in row-level security and audit logging as additional protective measures

# PostgreSQL configuration to enforce read-only at database level
# Create a read-only role for Superset connections
psql -c "CREATE ROLE superset_readonly WITH LOGIN PASSWORD 'secure_password';"
psql -c "GRANT CONNECT ON DATABASE your_database TO superset_readonly;"
psql -c "GRANT USAGE ON SCHEMA public TO superset_readonly;"
psql -c "GRANT SELECT ON ALL TABLES IN SCHEMA public TO superset_readonly;"
psql -c "ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO superset_readonly;"