Auth bypass in Pgbouncer

CVE-2026-107350

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.

Vulnerability class: Broken Authentication

Published .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

  • Pgbouncer

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-107350?
CVE-2026-107350 is a high-severity vulnerability in Pgbouncer, classified under Improper Authentication. CVSS score: 8.8/10. Published 2026-10-14.
How severe is CVE-2026-107350?
High severity. CVSS v3 base score is 8.8 out of 10.