CVE-2026-27860

dovecot: Dovecot: Authentication bypass and information disclosure via LDAP filter injection

Published Mar 27, 2026 CVSS 3.1 · 3.7 Low EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6197-1 dovecot security update
Ubuntu USN Ubuntu USN USN-8136-1 Dovecot vulnerabilities
History
Type Values Removed Values Added
First Time appeared Dovecot
Dovecot dovecot
Open-xchange dovecot
CPEs cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*
cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*
Vendors & Products Dovecot
Dovecot dovecot
Open-xchange dovecot
Type Values Removed Values Added
First Time appeared Open-xchange
Open-xchange ox Dovecot Pro
Vendors & Products Open-xchange
Open-xchange ox Dovecot Pro
Type Values Removed Values Added
Title LDAP Filter Injection in Open‑Xchange OX Dovecot Pro dovecot: Dovecot: Authentication bypass and information disclosure via LDAP filter injection
References
Metrics threat_severity

None

threat_severity

Low

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title LDAP Filter Injection in Open‑Xchange OX Dovecot Pro
Type Values Removed Values Added
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.
Weaknesses CWE-90
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
OX
Published
Updated
Mar 27, 2026, 12:33 PM
Reserved
Feb 24, 2026, 8:46 AM
Status
Analyzed
Published
Mar 27, 2026, 9:16 AM
Modified
Oct 26, 2026, 12:10 AM
Severity
Low
Public date
Mar 27, 2026, 8:10 AM