CVE-2026-61907: Medium severity Cyrus IMAP vulnerability
An issue was discovered in Cyrus IMAP before 3.12.4. JMAP snooze bypasses the destination-mailbox ACL. An authenticated user with insert permissions on another user's snoozed mailbox could cause insertion of mail to that user's inbox, or any other of their mailboxes whose id was known to the user, despite having no insert permissions to the target mailbox.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated user needs insert permission on another user's snoozed mailbox. The attacker must also know the identifier of the target mailbox they want mail inserted into.
What access can an attacker gain through this flaw?
The flaw allows insertion of mail into the other user's inbox or another mailbox whose identifier is known, even when the attacker does not have insert permission on that target mailbox. The provided information indicates an integrity impact, not a confidentiality or availability impact.
Which versions should be remediated?
Cyrus IMAP versions before 3.12.4 are affected. The supplied references also include release notes for 3.10.4, but the provided description does not state which 3.10 versions are affected or fixed.