---
title: "CVE-2026-6669\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-6669?format=md
keywords: index, follow
---

# CVE-2026-6669

Publication date 24 September 2026

Last updated 24 September 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**5.9 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2026-6669?format=md#impact-score)

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## Description

Missing upper bound on the key derivation iteration count accepted during
SCRAM authentication to a backend server in PgBouncer through 1.25.2 allows
a malicious or compromised PostgreSQL backend to cause uncontrolled CPU
consumption in PgBouncer. The resulting key derivation cannot be
interrupted in frontend builds such as PgBouncer. Because PgBouncer serves
all clients from a single process, one backend can in this way stop it from
serving traffic for every other database and client it is pooling, so the
failure of a single backend is not contained.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| pgbouncer | 26.04 LTS resolute | Needs evaluation |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.9 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | High |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | None |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.9 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-6669)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-6669)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-6669)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-6669)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-6669>
* <https://www.pgbouncer.org/changelog.html>