---
id: CVE-2026-6668
title: >-
  Integer overflow in the packet buffer growth logic in PgBouncer through 1.25.2
  allows an unauthenticated remote attacker to cause a denial of service
summary: >-
  Integer overflow in the packet buffer growth logic in PgBouncer through 1.25.2
  allows an unauthenticated remote attacker to cause a denial of service.
  Sufficiently large input makes the buffer size computation overflow, leaving
  the growt…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-190
  - CWE-835
product: PgBouncer
affected:
  - PgBouncer <= 1.25.2
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T19:40:10.000'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-6668'
references:
  - url: 'https://www.pgbouncer.org/changelog.html'
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6668.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-6668'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2539548'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-6668'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-6668'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T16:33:22.320321Z'
ingestedAt: '2026-09-23T16:27:22.664Z'
vendor: Red Hat
---

## Overview

Integer overflow in the packet buffer growth logic in PgBouncer through 1.25.2 allows an unauthenticated remote attacker to cause a denial of service. Sufficiently large input makes the buffer size computation overflow, leaving the growth loop unable to terminate. Because PgBouncer serves all clients from a single process, this saturates a CPU core and stalls every pooled connection until the process is killed. Both unauthenticated and authenticated code paths can reach the overflow.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Hardened Images · no fix planned: Red Hat Hardened Images · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6668.json)