Is CVE-2026-6669 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-6669 being exploited in the wild.

How severe is CVE-2026-6669?

Medium severity, with a CVSS score of 5.9, published 23 September 2026.

Is there a fix for CVE-2026-6669?

A patch was published on 2026-09-23: Fixed in PgBouncer 1.26.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-6669 attacked?

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

Am I affected by CVE-2026-6669?

Check whether you run 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-2026-6669: PgBouncer uncontrolled CPU consumption in SCRAM authentication

CVE-2026-6669 · Severity: medium · CVSS 5.9 · Published 2026-09-23

PgBouncer is a connection pooler that allows multiple clients to share database connections to PostgreSQL. A malicious or compromised PostgreSQL backend server can send an unbounded key derivation iteration count during SCRAM authentication, forcing PgBouncer to consume CPU resources uncontrollably. Since PgBouncer uses a single process to serve all clients, this causes complete service unavailability across all databases and clients until the process is killed.

Technologies: PgBouncer. Vendors: PgBouncer.

Quick answers

Is CVE-2026-6669 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-6669 being exploited in the wild.
How severe is CVE-2026-6669?: Medium severity, with a CVSS score of 5.9, published 23 September 2026.
Which products and versions are affected?: PgBouncer through 1.25.2.
Is there a fix for CVE-2026-6669?: A patch was published on 2026-09-23: Fixed in PgBouncer 1.26.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-6669 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-6669?: Check whether you run 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

The vulnerability exists in PgBouncer's SCRAM authentication handling, which fails to enforce an upper bound on the iteration count parameter sent by backend PostgreSQL servers. An attacker with control over a backend server can specify an arbitrarily large iteration count, causing PgBouncer to perform unbounded key derivation work that cannot be interrupted. The fix (in version 1.26.0) enforces a maximum iteration count of 1000000.

Affected products

PgBouncer PgBouncer through 1.25.2

Timeline

2026-09-23: disclosed
2026-09-23: patched: Fixed in PgBouncer 1.26.0

References

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

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