CVE-2026-27859

A mail message containing excessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU. A suitably formatted mail message causes mail delivery process to consume large amounts of CPU time. Use MTA capabilities to limit RFC 2231 MIME parameters in mail messages, or upgrade to fixed version where the processing is limited. No publicly available exploits are known.

Affected products

Dovecot, Linuxmint, Red Os, Ubuntu

Dovecot

< 2.4.3

Open-xchange Dovecot

< 3.0.5, 3.1.4

Fix

Available

CVSS 3.1

5.3 MEDIUM

EPSS

0.4% (31th percentile)

Weakness

CWE-400

NVD status

Analyzed

Published

2026-03-27