CVE-2026-2003: PostgreSQL Information Disclosure Flaw

CVE-2026-2003 Overview

CVE-2026-2003 is a memory information disclosure vulnerability in PostgreSQL caused by improper validation of the oidvector data type. This vulnerability allows an authenticated database user to potentially disclose a few bytes of server memory. While the PostgreSQL team has not ruled out the viability of attacks that arrange for confidential information to be present in the disclosed bytes, such scenarios are considered unlikely.

Critical Impact

Authenticated database users may exploit improper input validation in PostgreSQL's oidvector type handling to leak small amounts of server memory, potentially exposing sensitive information stored in adjacent memory regions.

Affected Products

• PostgreSQL versions before 18.2
• PostgreSQL versions before 17.8
• PostgreSQL versions before 16.12
• PostgreSQL versions before 15.16
• PostgreSQL versions before 14.21

Discovery Timeline

• February 12, 2026 - CVE-2026-2003 published to NVD
• February 12, 2026 - Last updated in NVD database

Technical Details for CVE-2026-2003

Vulnerability Analysis

This vulnerability stems from CWE-1287 (Improper Validation of Specified Type of Input), specifically in how PostgreSQL handles the oidvector data type. The oidvector type is an internal PostgreSQL type used to store arrays of object identifiers (OIDs), primarily utilized in system catalogs. When input validation for this type is insufficient, an authenticated user can craft malicious input that causes the database server to read and return memory beyond the intended buffer boundaries.

The attack requires low-privilege database access and can be executed remotely over the network without user interaction. While the information disclosed is limited to a few bytes per exploitation attempt, repeated exploitation could potentially accumulate enough data to be meaningful in specific attack scenarios.

Root Cause

The root cause lies in improper boundary checking when parsing and processing oidvector type values. PostgreSQL's type handling routines fail to adequately validate the structure and length of oidvector input, allowing specially crafted values to trigger out-of-bounds read operations. This results in the server returning data from unintended memory locations, which may contain remnants of previous operations, query data, or other potentially sensitive information.

Attack Vector

The vulnerability is exploitable over the network by any authenticated database user. An attacker with valid database credentials can submit specially crafted SQL queries or data manipulation operations involving the oidvector type. The attack does not require any special privileges beyond basic database access, making it accessible to low-privilege users. The attack complexity is low, and no user interaction is required for successful exploitation.

The vulnerability manifests in PostgreSQL's oidvector type validation routines. Attackers can craft malicious input that bypasses boundary validation, causing the database to read and return memory beyond intended buffer limits. For detailed technical information, refer to the PostgreSQL Security Advisory.

Detection Methods for CVE-2026-2003

Indicators of Compromise

• Unusual queries or operations involving the oidvector data type from unexpected users or applications
• Abnormal patterns in PostgreSQL error logs related to type conversion or validation failures
• Database queries with malformed or unusually structured oidvector values
• Repeated attempts to access system catalog tables that utilize oidvector columns

Detection Strategies

• Monitor PostgreSQL query logs for suspicious operations involving oidvector type casting or manipulation
• Implement database activity monitoring (DAM) solutions to detect anomalous query patterns targeting internal data types
• Review audit logs for unauthorized access attempts to system catalogs such as pg_index and pg_proc
• Deploy SentinelOne Singularity to detect post-exploitation activity and suspicious database server behavior

Monitoring Recommendations

• Enable detailed query logging in PostgreSQL with log_statement = 'all' for forensic analysis capabilities
• Configure alerting for failed authentication attempts and unusual connection patterns to the database server
• Monitor system resource usage for signs of memory scanning or repeated exploitation attempts
• Implement network segmentation to limit database access to authorized application servers only

How to Mitigate CVE-2026-2003

Immediate Actions Required

• Upgrade PostgreSQL to the latest patched versions: 18.2, 17.8, 16.12, 15.16, or 14.21 immediately
• Audit database user permissions and revoke unnecessary access, particularly for users who do not require direct database connectivity
• Review application code for any custom usage of oidvector type and validate input handling
• Implement network-level access controls to restrict database connectivity to trusted hosts only

Patch Information

PostgreSQL has released security updates addressing this vulnerability. Organizations should upgrade to the following minimum versions:

For detailed patch information and download links, refer to the PostgreSQL Security Advisory.

Workarounds

• Restrict database access to only essential users and applications while planning the upgrade
• Implement additional monitoring and logging for database operations involving internal data types
• Consider deploying a database firewall or proxy to filter potentially malicious queries
• Isolate affected PostgreSQL instances on separate network segments with enhanced monitoring

# Configuration example
# Restrict PostgreSQL connections to trusted hosts only
# Edit pg_hba.conf to limit access:

# TYPE  DATABASE        USER            ADDRESS                 METHOD
host    all             all             192.168.1.0/24          scram-sha-256
host    all             all             0.0.0.0/0               reject

# Reload PostgreSQL configuration after changes
sudo systemctl reload postgresql