CVE-2021-3935: Debian Linux

High severity, CVSS 8.1. EPSS: 1.1% chance of exploitation in the next 30 days.

When PgBouncer is configured to use "cert" authentication, a man-in-the-middle attacker can inject arbitrary SQL queries when a connection is first established, despite the use of TLS certificate verification and encryption. This flaw affects PgBouncer versions prior to 1.16.1.

Affected products

• Debian Debian Linux: version 9.0 only
• Fedoraproject Fedora: version 35 only
• Pgbouncer Pgbouncer: before 1.16.1 (fixed in 1.16.1)
• Red Hat Enterprise Linux: version 7.0 only

Published 2021-11-22. Last modified 2026-06-17.