Integer Overflow Vulnerability in PgBouncer Affects Unauthenticated Remote Access
CVE-2026-6664

7.5HIGH

Key Information:

Vendor

PgBouncer

Status
Pgbouncer
Vendor
CVE Published:
9 May 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-6664?

An integer overflow vulnerability exists in the network packet parsing code of PgBouncer versions prior to 1.25.2, which allows a bypass of boundary checks. This flaw can enable an unauthenticated remote attacker to send a malformed SCRAM authentication packet, potentially causing the PgBouncer service to crash. It is crucial for users to address this vulnerability by upgrading to the latest version to ensure system integrity and availability.

Affected Version(s)

PgBouncer 0 < 1.25.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

bouncer-overflow
Created by nicolasjulian

References

https://www.pgbouncer.org/changelog.html#pgbouncer-125x

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Thanks to Johannes Möller for finding and reporting this problem.
.