CVE-2026-61911: Exposure of Sensitive System Information to an Unauthorized Control Sphere

An issue was discovered in Cyrus IMAP before 3.12.4. There is a Sieve mailbox existence oracle. An authenticated user could install a Sieve script that probed whether another user's private mailbox existed, or read the value of shared mailbox annotations, by observing which fileinto branch fired...

CVE-2026-61909

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...

EUVD-2026-75139

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...

CVE-2026-61907: Incorrect Authorization

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...

EUVD-2026-75168

An issue was discovered in Cyrus IMAP before 3.12.4. There is a VPATCH BYPARAM double-free. An authenticated calendar user could crash a Cyrus CalDAV worker with a PATCH containing PATCH-ACTION="BYPARAM@..." against a resource with two or more properties of the matched kind. The memory holding th...

CVE-2026-61907

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...

PT-2026-89140

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.4 Description An issue exists where the Mailbox/set function allows a sharee to modify a special-use role on shared mailboxes. An authenticated user possessing the maySetKeywords permission on another user's...

CVE-2026-61915: Double Free

An issue was discovered in Cyrus IMAP before 3.12.4. There is a VPATCH BYPARAM double-free. An authenticated calendar user could crash a Cyrus CalDAV worker with a PATCH containing PATCH-ACTION="BYPARAM@..." against a resource with two or more properties of the matched kind. The memory holding th...

CVE-2026-61909

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...

PT-2026-89141

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.4 Description A Sieve mailbox existence oracle exists where an authenticated user can install a Sieve script to determine if another user's private mailbox exists or read the value of shared mailbox annotation...

CVE-2026-61909: Unprotected Alternate Channel

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...

CVE-2026-61907

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...

CVE-2026-61910

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...

CVE-2026-61908

An issue was discovered in Cyrus IMAP before 3.12.4. A JMAP email-header blob ID can reference an out-of-bounds index. An authenticated user could attempt to download a crafted JMAP blob ID of the form H-, which could read past the end of the internal blobheaders array during download, exposing...

CVE-2026-61909

Cyrus IMAP before 3.12.4 (backported to 3.10.4 and 3.8.8) contains an ACL bypass in its CalDAV/CardDAV multiget functionality. An authenticated DAV user who holds some shared access to another user's calendar or address book can read unshared events or contacts by including target hrefs in a cale...

CVE-2026-61907

This vulnerability affects Cyrus IMAP prior to version 3.12.4 , where the JMAP snooze operation bypasses the destination-mailbox ACL . An authenticated user who holds insert permissions on another user's snoozed mailbox can force mail insertion into that user's inbox or any other mailbox whose ID...

PT-2026-89142

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.4 Description A double-free issue exists in the VPATCH BYPARAM functionality. An authenticated calendar user can cause a Cyrus CalDAV worker to crash by sending a PATCH request containing...

CVE-2026-61908

An issue was discovered in Cyrus IMAP before 3.12.4. A JMAP email-header blob ID can reference an out-of-bounds index. An authenticated user could attempt to download a crafted JMAP blob ID of the form H-, which could read past the end of the internal blobheaders array during download, exposing...

CVE-2026-61909

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...

CVE-2026-61907

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...