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-2026-61915

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...

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...

PT-2026-89126

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.4 Description A flaw exists where JMAP snooze bypasses the destination-mailbox Access Control List ACL. An authenticated user who possesses insert permissions on another user's snoozed mailbox can insert mail...

EUVD-2026-75130

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

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.4 Description An issue exists where CalDAV and CardDAV multiget operations bypass per-href Access Control Lists ACL. An authenticated DAV user who has partial shared access to another user's address book or...

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...

CVE-2026-61908: Out-of-bounds Read

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

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-2026-61910: 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...

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-2026-61915

Cyrus IMAP before 3.12.4 is affected by a VPATCH BYPARAM double-free in the CalDAV worker. An authenticated calendar user can trigger a crash by sending a PATCH request with PATCH-ACTION="BYPARAM@..." against a resource that has two or more properties of the matched kind, causing the memory holdi...

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-2026-61909

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-2026-61910

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 out-of-bounds read vulnerability in Cyrus IMAP before 3.12.4 (also fixed in 3.10.4 and 3.8.8) allows an authenticated user to download a crafted JMAP email-header blob ID of the form H-, which reads past the end of the internal blob_headers array, potentially exposing adjacent heap memory . NV...

PT-2026-89135

Name of the Vulnerable Software and Affected Versions Cyrus IMAP versions prior to 3.12.4 Description An authenticated user can trigger an out-of-bounds index reference using a crafted JMAP email-header blob ID. By requesting a blob ID in the format H-, the system may read past the end of the...

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-2026-61908

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

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...