CVE-2026-22015: MySQL Server Information Disclosure Flaw

CVE-2026-22015 Overview

CVE-2026-22015 is an Information Disclosure vulnerability affecting Oracle MySQL Server's Information Schema component. This vulnerability allows a low-privileged attacker with network access to gain unauthorized read access to a subset of MySQL Server accessible data. The flaw exists in the Server: Information Schema component, which is responsible for providing access to database metadata.

Critical Impact

Low-privileged attackers can exploit this vulnerability via network protocols to access sensitive database metadata and information that should be restricted, potentially exposing confidential database schema details and other protected data.

Affected Products

• Oracle MySQL Server versions 8.0.0 through 8.0.45
• Oracle MySQL Server versions 8.4.0 through 8.4.8
• Oracle MySQL Server versions 9.0.0 through 9.6.0

Discovery Timeline

• 2026-04-21 - CVE-2026-22015 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2026-22015

Vulnerability Analysis

This vulnerability resides in the Information Schema component of MySQL Server. The Information Schema is a virtual database that provides metadata about all other databases, tables, columns, and server status information. The flaw enables authenticated users with minimal privileges to access data they should not be authorized to view.

The vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), indicating an improper access control issue that allows information to be disclosed to actors who should not have access to it. In this case, the Information Schema queries can return data elements that exceed the privilege boundaries of the requesting user.

Root Cause

The root cause stems from insufficient privilege validation within the Information Schema query processing. When certain queries are made against the Information Schema views, the authorization checks fail to properly restrict the result set to only data the user is entitled to access. This allows low-privileged users to retrieve metadata about database objects or data subsets they should not have visibility into.

Attack Vector

This vulnerability is exploitable over the network via standard MySQL protocols. An attacker needs only low-level privileges (such as a basic authenticated database user account) to exploit this flaw. No user interaction is required, making it straightforward for any authenticated user to craft queries against the Information Schema that return unauthorized data.

The attack can be carried out through standard MySQL client connections, applications using MySQL connectors, or any interface that allows SQL query execution. Since the vulnerability requires only basic authentication, any compromised or malicious low-privilege account can be leveraged for exploitation.

Detection Methods for CVE-2026-22015

Indicators of Compromise

• Unusual or frequent queries against INFORMATION_SCHEMA tables from low-privileged accounts
• Database audit logs showing access to schema metadata by users without administrative roles
• Anomalous patterns of metadata enumeration queries that exceed normal application behavior

Detection Strategies

• Enable MySQL General Query Log or Slow Query Log to capture Information Schema queries for review
• Implement database activity monitoring (DAM) solutions to flag suspicious metadata access patterns
• Review MySQL audit plugin logs for queries accessing sensitive Information Schema tables
• Monitor for bulk or scripted queries against INFORMATION_SCHEMA from non-administrative accounts

Monitoring Recommendations

• Configure alerts for Information Schema queries from accounts that typically do not require metadata access
• Establish baseline query patterns for each database user and alert on deviations
• Integrate MySQL logs with SIEM solutions for centralized monitoring and correlation

How to Mitigate CVE-2026-22015

Immediate Actions Required

• Update Oracle MySQL Server to patched versions as specified in the Oracle Security Alert April 2026
• Review and minimize privileges for all database user accounts following the principle of least privilege
• Audit existing database users and remove unnecessary accounts or excessive permissions
• Enable MySQL audit logging to track Information Schema access while awaiting patch deployment

Patch Information

Oracle has released security patches addressing CVE-2026-22015 as part of the April 2026 Critical Patch Update. Administrators should apply the relevant patch for their MySQL Server version:

• MySQL Server 8.0.x: Upgrade to version 8.0.46 or later
• MySQL Server 8.4.x: Upgrade to version 8.4.9 or later
• MySQL Server 9.x: Upgrade to version 9.6.1 or later

Refer to the Oracle Security Alert April 2026 for complete patch details and download links.

Workarounds

• Restrict network access to MySQL Server using firewall rules to limit connections to trusted hosts only
• Revoke unnecessary privileges from user accounts, particularly SELECT privileges that may extend to Information Schema
• Implement database proxy solutions that can filter or restrict Information Schema queries

# Configuration example - Restrict user privileges
# Revoke broad SELECT privileges and grant only specific table access
mysql -u root -p -e "REVOKE ALL PRIVILEGES ON *.* FROM 'app_user'@'%';"
mysql -u root -p -e "GRANT SELECT, INSERT, UPDATE ON mydb.* TO 'app_user'@'%';"
mysql -u root -p -e "FLUSH PRIVILEGES;"