PT-2026-89135

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 blob headers array during download, exposing...

CVE-2026-61911

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...

EUVD-2026-75129

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-2026-61911: 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-2026-61907

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...

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...

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-2026-61908

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-2026-61910

Cyrus IMAP before 3.12.4 is affected by a flaw in the Mailbox/set command, where an authenticated user holding the maySetKeywords privilege on another user's mailbox can alter its special-use annotation . This allows the sharee to reassign the shared mailbox to roles such as archived or snoozed ,...

CVE-2026-61915

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...

EUVD-2026-75134

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...

PT-2026-89140

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...

PT-2026-89136

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-2026-89142

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

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-2026-61911

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-2026-61911

Cyrus IMAP before 3.12.4 is affected by a Sieve mailbox existence oracle . An authenticated user can install a Sieve script that probes whether another user's private mailbox exists, or read the value of shared mailbox annotations , by observing which fileinto branch fires during LMTP delivery. T...

CVE-2026-61910: Incorrect Authorization

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...

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...