CVE-2026-107350 — Authentication bypass via second StartupMessage during SCRAM authentication in PgBouncer
Improper authentication in PgBouncer 1.17.0 through 1.26.0 allows a remote attacker who knows the password of a user listed in auth_file to log in as any other user that authent…
Published: 2026-10-14 · CVSS: 8.8 · CVSS 3.1
Improper authentication in PgBouncer 1.17.0 through 1.26.0 allows a remote attacker who knows the password of a user listed in auth_file to log in as any other user that authenticates using SCRAM, including PgBouncer admin users and backend superusers. A second StartupMessage sent during SCRAM authentication against a non-existent database is not rejected and switches the user being logged in as, while the SCRAM exchange is still verified against the keys of the first user.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7