CVE-2026-47086

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.3

Description An issue exists where tokens issued via the GENURLAUTH command can bypass Access Control Lists (ACLs). An authenticated user can generate a URLAUTH token for any specified mailbox, regardless of whether they have read access. This allows the unauthorized reading of emails from mailboxes for which the user has no granted permissions.

Recommendations Update Cyrus IMAP to version 3.12.3 or later. As a temporary mitigation, restrict the use of the GENURLAUTH command.