CVE-2026-107314

A flaw was found in the PostgreSQL JDBC Driver (pgjdbc), which may lead to information disclosure. When the requireAuth connection property is configured to exclude all supported authentication mechanisms or lacks a valid method, the driver fails to enforce authentication restrictions and accepts any method requested by the server. A man-in-the-middle attacker positioned between the application and the database server can exploit this flaw by requesting cleartext password authentication to intercept database credentials.

This vulnerability is evaluated as a Moderate severity flaw rather than Important because successful exploitation requires both an uncommon configuration and a man-in-the-middle network position. By default, the requireAuth property is unset in standard deployments, leaving applications secure in standard configurations. The failure to enforce authentication restrictions only manifests when administrators explicitly configure requireAuth to negate all known authentication mechanisms or supply invalid syntax. Furthermore, capturing database credentials necessitates an active adversary situated to intercept and manipulate client-to-server database network traffic.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, ensure database connection configurations do not use empty values or negation lists that exclude all supported authentication mechanisms in the requireAuth property. Instead, configure an explicit allowlist specifying only approved authentication methods (such as requireAuth=scram-sha-256) or omit the property entirely if default driver behavior is acceptable.

Additionally, protect connection traffic against man-in-the-middle interception by configuring TLS/SSL with full certificate validation on the JDBC connection string (for example, setting sslmode=verify-full).

Caveat: Ensure the PostgreSQL server is configured to support the chosen authentication method and SSL requirements before altering client connection parameters. Modifying connection properties in application configuration files requires restarting the affected application service.