# CVE-2026-6664: PgBouncer integer overflow in SCRAM packet parsing

Source: https://junglewise.ai/threats/cve-2026-6664-pgbouncer-integer-overflow-in-scram-packet-parsing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-09. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-6664 · Severity: high · CVSS 7.5 · Published 2026-05-09

PgBouncer, a popular connection pooler for PostgreSQL databases, is vulnerable to a flaw that allows an attacker to crash the service remotely. By sending a specially crafted authentication packet, an unauthenticated user can trigger a system failure, leading to a denial of service for all applications relying on the database connection pool. This can disrupt business operations and prevent legitimate users from accessing database resources.

Technologies: [PostgreSQL PgBouncer](https://junglewise.ai/threats/technologies/pgbouncer). Vendors: [PostgreSQL](https://junglewise.ai/threats/vendors/postgresql).

## Quick answers

**Is CVE-2026-6664 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-6664 being exploited in the wild.

**How severe is CVE-2026-6664?** High severity, with a CVSS score of 7.5, published 9 May 2026.

**Which products and versions are affected?** PostgreSQL PgBouncer before 1.25.2.

**Is there a fix for CVE-2026-6664?** A patch was published on 2026-05-08: PgBouncer version 1.25.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-6664 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-6664?** Check whether you run PostgreSQL PgBouncer at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An integer overflow vulnerability exists in the network packet parsing logic of PgBouncer versions prior to 1.25.2. The flaw is located within the code responsible for handling SCRAM authentication packets, where an integer overflow allows an attacker to bypass a boundary check. A remote, unauthenticated attacker can exploit this by sending a malformed SCRAM authentication packet, resulting in a daemon crash (Denial of Service). The vulnerability is tracked as CWE-190. Users should upgrade to PgBouncer version 1.25.2 or later to resolve the issue.

## Affected products

- PostgreSQL PgBouncer before 1.25.2

## Timeline

- 2026-05-08: patched: PgBouncer version 1.25.2 released
- 2026-05-09: disclosed: CVE-2026-6664 published

## References

- [https://www.pgbouncer.org/changelog.html](https://www.pgbouncer.org/changelog.html)

## Related threats

- [PgBouncer missing authorization for KILL_CLIENT admin command](https://junglewise.ai/threats/cve-2026-6667-pgbouncer-missing-authorization-for-kill-client-admin-command)
- [PgBouncer null pointer dereference via malformed server error response](https://junglewise.ai/threats/cve-2026-6666-pgbouncer-null-pointer-dereference-via-malformed-server-error)
- [PgBouncer stack overflow in SCRAM authentication](https://junglewise.ai/threats/cve-2026-6665-pgbouncer-stack-overflow-in-scram-authentication)