Threat Intelligence Database

An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget bypasses a per-href ACL. An authenticated DAV user with some shared access to another user's calendar or address book could read even unshared events or contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT.

CVE-2026-61915 is a medium severity vulnerability in Cyrus IMAP before version 3.12.4 involving a double-free memory error. An authenticated calendar user can cause a crash in the Cyrus CalDAV worker by sending a PATCH request with a specific PATCH-ACTION parameter against a resource containing multiple properties of the same kind. This leads to the memory holding the selector being freed multiple times during iteration.

An issue was discovered in Cyrus IMAP before 3.12.4. Mailbox/set let a sharee change a special-use role on shared mailboxes. An authenticated user with maySetKeywords on another user's mailbox could change that mailbox's specialuse annotation. This could allow the sharee to change the shared mailbox to perform the archived, snoozed, or other role, which might cause mail mail to be written to the shared mailbox, sharing more content than intended. (This is likely to be an unusual situation, made more unusual because if the target already has an non-shared mailbox with that role, role duplication suppression will prevent the update.)

An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. URLAUTH does not honor revoked authorizer access. A URLAUTH URL minted while the authorizer had access continued to work after that access was revoked.