PT-2026-40027 · Dovecot · Dovecot

Published 2026-05-12 · Updated 2026-06-02 · CVE-2026-40016

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions dovecot versions prior to 2.4.4-1.1

Description An attacker can upload a malicious Sieve script via the 'ManageSieve' service or local access to bypass configured CPU time limits for Sieve by up to 130 times the limit. This can lead to degraded server performance.

Recommendations Update to version 2.4.4-1.1. Prevent direct access to Sieve scripts via 'ManageSieve' or local access.

Fix

Resource Exhaustion

Weakness Enumeration

CWE-400

Related Identifiers

CVE-2026-40016

OPENSUSE-SU-2026:10766-1

USN-8365-1

Affected Products

Dovecot

References · 21

• https://ubuntu.com/security/CVE-2026-40020 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-40016 · Security Note
• https://ubuntu.com/security/notices/USN-8365-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-40016 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-40016 · Vendor Advisory
• https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-40016 · Security Note
• https://ubuntu.com/security/CVE-2026-33603 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-42006 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:10766-1 · Vendor Advisory
• https://osv.dev/vulnerability/USN-8365-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-40016 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-40016 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-27851 · Vendor Advisory
• https://suse.com/security/cve/CVE-2026-42006 · Note