CVE-2026-40020

LOW

OX Dovecot Pro < 2.3.0 - Improper Access Control via IMAP SETACL Command

Title source: llm
STIX 2.1

Description

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.

References (1)

Core 1

Scores

CVSS v3 3.1
EPSS 0.0001
EPSS Percentile 2.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-284
Status published
Products (3)
dovecot/dovecot < 2.4.4
open-xchange/dovecot < 3.1.5
Open-Xchange GmbH/OX Dovecot Pro < 2.3.0
Published May 12, 2026
Tracked Since May 12, 2026