---
id: CVE-2026-107350
title: >-
  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
  back…
summary: >-
  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
  back…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-287
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T18:17:25.670'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107350'
references:
  - url: 'https://www.pgbouncer.org/changelog.html'
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-14T18:47:39.310Z'
product: PgBouncer
affected:
  - PgBouncer >= 1.17.0 < 1.26.1
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.