CVE-2026-40020

medium Red Hat
CVSS v3 Base Score
6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score
0.0%
Exploitation probability in 30 days
Top 97% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Published: May 12, 2026 (58 days ago)
Last Modified: May 12, 2026
Vendor: Red Hat
Source: REDHAT

Description

A flaw was found in dovecot. A remote attacker can exploit the Internet Message Access Protocol (IMAP) SETACL command to inject "anyone" permissions into a user's dovecot-acl file, even when the imap_acl_allow_anyone setting is disabled. This vulnerability allows an attacker to spam folders to all users, leading to a denial of service by disrupting normal email service. No unauthorized access to user data is gained.

CWE

CWE-88

Affected Products

Red Hat Enterprise Linux 10Red Hat Enterprise Linux 6Red Hat Enterprise Linux 8Red Hat Enterprise Linux 9

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov 🔗 documentation.open-xchange.com