CVE-2026-27860

If auth_username_chars is empty, it is possible to inject arbitrary LDAP filter to Dovecot's LDAP authentication. This leads to potentially bypassing restrictions and allows probing of LDAP structure. Do not clear out auth_username_chars, or install fixed version. No publicly available exploits are known.

Affected products

Dovecot, Linuxmint, Ubuntu

Dovecot

< 2.4.3

Open-xchange Dovecot

< 3.1.4

Fix

Available

CVSS 3.1

5.3 MEDIUM

EPSS

0.3% (21th percentile)

Weakness

CWE-90

NVD status

Analyzed

Published

2026-03-27