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.
Fix
Microsoft's update · Important
- Release Notes — azl3 pgbouncer 1.25.2-1 on Azure Linux 3.0 · build 1.26.1-1
From the 2026-Oct release note of Microsoft's Security Update Guide, revised 2026-10-28.
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 2
- StatusReceived → Awaiting AnalysisNVD modified 2026-10-15 16:32
- First seenCVSS 8.8NVD modified 2026-10-14 18:17
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.