Is CVE-2026-6665 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-6665 being exploited in the wild.

How severe is CVE-2026-6665?

High severity, with a CVSS score of 8.1, published 9 May 2026.

Which products and versions are affected?

PostgreSQL PgBouncer < 1.25.2, before 1.25.2.

Is there a fix for CVE-2026-6665?

A patch was published on 2026-05-08: Fixed in PgBouncer 1.25.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-6665 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-6665?

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.

CVE-2026-6665: PgBouncer stack overflow in SCRAM authentication

Q: Is there a fix for CVE-2026-6665?

A patch was published on 2026-05-08: Fixed in PgBouncer 1.25.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-6665 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-6665?

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.

CVE-2026-6665 · Severity: high · CVSS 8.1 · Published 2026-05-09

PgBouncer, a popular connection pooler for PostgreSQL databases, contains a security flaw in how it handles secure authentication. A malicious or compromised database server could send a specially crafted message to PgBouncer that causes the service to crash or potentially allows for unauthorized code execution. This could lead to a service outage or a compromise of the gateway that manages database traffic.

Technologies: PostgreSQL PgBouncer. Vendors: PostgreSQL.

Quick answers

Is CVE-2026-6665 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-6665 being exploited in the wild.
How severe is CVE-2026-6665?: High severity, with a CVSS score of 8.1, published 9 May 2026.
Which products and versions are affected?: PostgreSQL PgBouncer < 1.25.2, before 1.25.2.
Is there a fix for CVE-2026-6665?: A patch was published on 2026-05-08: Fixed in PgBouncer 1.25.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-6665 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-6665?: 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

A stack-based buffer overflow (CWE-121) exists in PgBouncer versions prior to 1.25.2. The vulnerability is located in the SCRAM authentication implementation, where the code fails to correctly validate the return value of the strlcat() function while constructing the 'client-final-message'. An attacker controlling a malicious backend database server can send a 'server-final-message' containing an excessively long nonce to trigger the overflow. While the attack requires a compromised or malicious backend (High Attack Complexity), it can result in a complete loss of availability or potential remote code execution on the PgBouncer host. The issue is resolved in version 1.25.2.

Affected products

PostgreSQL PgBouncer < 1.25.2

Timeline

2026-05-08: patched: Fixed in PgBouncer 1.25.2
2026-05-09: disclosed: CVE published

References

https://www.pgbouncer.org/changelog.html

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