CVE-2026-27860

LOW

OX Dovecot Pro <3.1.0 - Auth Bypass

Title source: llm
STIX 2.1

Description

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.

Scores

CVSS v3 3.7
EPSS 0.0002
EPSS Percentile 6.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-90
Status published
Products (4)
dovecot/dovecot < 2.4.3
open-xchange/dovecot < 3.1.4
Open-Xchange GmbH/OX Dovecot Pro < 2.4.0
Open-Xchange GmbH/OX Dovecot Pro < 3.1.0
Published Mar 27, 2026
Tracked Since Mar 27, 2026