CVE-2026-107350
Authentication bypass via second StartupMessage during SCRAM authentication in PgBouncer
- State
- Published
- Severity
- 8.8 High
- Published
- Oct 14, 2026
- Updated
- Oct 16, 2026
- Reserved
- Oct 7, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | PostgreSQL |
Weaknesses
- CWE-287 Improper Authentication
Affected Products
| Product | Versions |
|---|---|
PgBouncern/a |
|
References
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