Linux Distros Unpatched Vulnerability : CVE-2026-6669

medium Nessus Plugin ID 350222

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- 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. (CVE-2026-6669)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://security-tracker.debian.org/tracker/CVE-2026-6669

https://ubuntu.com/security/CVE-2026-6669

Plugin Details

Severity: Medium

ID: 350222

File Name: unpatched_CVE_2026_6669.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 9/25/2026

Updated: 9/25/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.61

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

CVSS Score Source: CVE-2026-6669

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.4

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:canonical:ubuntu_linux:pgbouncer, p-cpe:/a:debian:debian_linux:pgbouncer

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 9/23/2026

Reference Information

CVE: CVE-2026-6669