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    CVE-2026-40014

    An attacker that can send mail to a user can craft a message header that makes the IMAP THREAD command consume CPU disproportionate to the size of the message. When a mail client issues a THREAD command on the affected mailbox, this can cause degradation or denial of service for IMAP. Monitor system for abnormal CPU usage, kill the offending process and remove the offending message from the affected mailbox. Update to non-vulnerable version. No publicly available exploits are known.

    Published:Aug 28, 2026
    Last Modified:Sep 1, 2026
    EPS:Aug 28, 2026
    EPSS Score:0.00272
    CVSS Score:6.5

    Affected Products

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

    Exploits

    No exploit reference

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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