PgBouncer 1.26.1 released - Fixes three CVEs

PgBouncer 1.26.1 has been released. This release fixes three CVEs:

1. CVE-2026-107350: Authentication bypass, allowing a client that knows the password of one SCRAM user to log in as any other SCRAM user, including admins and backend superusers. Caused by a second StartupMessage being processed during SCRAM authentication when connecting to a non-existent database.
2. CVE-2026-107349: DoS due to infinite loop, triggerable by unauthenticated clients. Caused by an empty option name in the startup options parameter, when ignore_startup_parameters is non-empty but does not contain options.
3. CVE-2026-107348: DoS due to infinite loop, triggerable by unauthenticated clients. Caused by an integer overflow in the packet buffer growth logic, only when max_packet_size is set above its default.

It also makes ignore_startup_parameters take precedence over tracked parameters, so that ignore_startup_parameters = search_path restores the 1.25 behaviour of ignoring search_path.

See https://www.pgbouncer.org/2026/10/pgbouncer-1-26-1 for more information, the detailed changelog, and download links.