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    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.

    Published:Mar 27, 2026
    Last Modified:Apr 29, 2026
    EPS:Mar 27, 2026
    EPSS Score:0.00065
    CVSS Score:3.7

    Affected Products

    Vendor
    Dovecot
    Product
    Dovecot
    Vendor
    Open-xchange
    Product
    Dovecot
    Vendor
    Open-xchange
    Product
    Ox Dovecot Pro

    Exploits

    No exploit reference

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-136 LDAP Injection

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    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High