Linux Distros Unpatched Vulnerability : CVE-2026-40020

medium Nessus Plugin ID 315683

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.

- Attacker can use the IMAP SETACL command to inject the anyone permission to user's dovecot-acl file even if imap_acl_allow_anyone=no. This causes folders to be spammed to all users. The impact is limited to being able to spam folders to other users, no unexpected access is gained. Install to fixed version. No publicly available exploits are known. (CVE-2026-40020)

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://access.redhat.com/security/cve/cve-2026-40020

https://security-tracker.debian.org/tracker/CVE-2026-40020

https://ubuntu.com/security/CVE-2026-40020

Plugin Details

Severity: Medium

ID: 315683

File Name: unpatched_CVE_2026_40020.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Misc.

Published: 5/20/2026

Updated: 5/21/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.2

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-40020

CVSS v3

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 4

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, cpe:/o:redhat:enterprise_linux:6, cpe:/o:redhat:enterprise_linux:8, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:centos:centos:dovecot, p-cpe:/a:centos:centos:dovecot-devel, p-cpe:/a:centos:centos:dovecot-mysql, p-cpe:/a:centos:centos:dovecot-pgsql, p-cpe:/a:centos:centos:dovecot-pigeonhole, p-cpe:/a:debian:debian_linux:dovecot, p-cpe:/a:canonical:ubuntu_linux:dovecot, p-cpe:/a:redhat:enterprise_linux:dovecot, p-cpe:/a:redhat:enterprise_linux:dovecot-devel, p-cpe:/a:redhat:enterprise_linux:dovecot-mysql, p-cpe:/a:redhat:enterprise_linux:dovecot-pgsql, p-cpe:/a:redhat:enterprise_linux:dovecot-pigeonhole, cpe:/o:centos:centos:8, cpe:/o:canonical:ubuntu_linux:14.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:redhat:enterprise_linux:9, cpe:/o:debian:debian_linux:12.0, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:debian:debian_linux:13.0, cpe:/o:redhat:enterprise_linux:10, cpe:/o:debian:debian_linux:14.0, cpe:/o:canonical:ubuntu_linux:25.10, cpe:/o:canonical:ubuntu_linux:26.04

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: 5/12/2026

Reference Information

CVE: CVE-2026-40020