CVE-2026-33607

CVE-2026-33607 affects Open-Xchange Dovecot , where an authenticated attacker can abuse the IMAP LIST command to consume excessive CPU, causing degradation or denial of service for IMAP. The vulnerability requires low privileges (valid credentials) and is network-reachable with low complexity, ra...

CVE-2026-33607

An attacker that has valid credentials can use IMAP LIST command to consume CPU. This can cause degradation or denial of service for IMAP. Monitor system for abnormal CPU usage and kill the offending process and lock account. Alternatively install fixed version. No publicly available exploits are...

CVE-2026-27852

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit...

CVE-2026-27852

CVE-2026-27852 affects Dovecot (Open-Xchange), the IMAP mail server. An attacker who can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters , causing excessive memory consumption when the message is later parsed. Although the me...

EUVD-2026-67657

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit...

CVE-2026-27852

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit...

CVE-2026-27852

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit...

UBUNTU-CVE-2026-40203

When IMAP compression is enabled, the same compression state is reused across responses in a session, so response sizes depend on both attacker-supplied mail and other mail in the same mailbox. An attacker that can send mail to a user and can also observe the sizes of that user's IMAP traffic can...

PT-2026-83057

Name of the Vulnerable Software and Affected Versions dovecot versions prior to 2.4.5-1.1 Description An attacker can craft a message header that causes the IMAP THREAD command to consume CPU resources disproportionate to the message size. When a mail client executes the THREAD command on the...

PT-2026-83062

Name of the Vulnerable Software and Affected Versions dovecot versions prior to 2.4.5-1.1 Description When IMAP compression is enabled, the compression state is reused across responses in a session. This causes response sizes to depend on both attacker-supplied mail and other mail within the same...

CVE-2026-40203

When IMAP compression is enabled, the same compression state is reused across responses in a session, so response sizes depend on both attacker-supplied mail and other mail in the same mailbox. An attacker that can send mail to a user and can also observe the sizes of that user's IMAP traffic can...

CVE-2026-52687

An attacker that has valid credentials can select a compression algorithm for the IMAP connection whose decompression state requires a large amount of memory, and open several such connections. The memory limit of the process is reached with only a few connections, terminating the process and all...

CVE-2026-42391

An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, which causes memory and CPU usage to grow disproportionately. The login process can be terminated by the out-of-memory handling, which also terminates all other connections handled by...

CVE-2026-40015: Out-of-bounds Read

An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause...

CVE-2026-42392: Exposure of Sensitive Information to an Unauthorized Actor

An attacker that has valid credentials can send an invalid IMAP URLFETCH command, which causes uninitialized memory to be included in the error response returned to the client. Process memory contents can be disclosed to the client, which may include sensitive data. Disable the IMAP URLAUTH...

UBUNTU-CVE-2026-42391

An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, which causes memory and CPU usage to grow disproportionately. The login process can be terminated by the out-of-memory handling, which also terminates all other connections handled by...

UBUNTU-CVE-2026-40015

An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause...

UBUNTU-CVE-2026-40017

An attacker that can send mail to a user can craft a message header whose values are chosen to collide in an internal hash table, which makes the IMAP THREAD command consume CPU disproportionate to the size of the message. This is a separate issue from CVE-2026-40014 and is not addressed by that...

UBUNTU-CVE-2026-42392

An attacker that has valid credentials can send an invalid IMAP URLFETCH command, which causes uninitialized memory to be included in the error response returned to the client. Process memory contents can be disclosed to the client, which may include sensitive data. Disable the IMAP URLAUTH...

CVE-2026-40203: Exposure of Sensitive Information to an Unauthorized Actor

When IMAP compression is enabled, the same compression state is reused across responses in a session, so response sizes depend on both attacker-supplied mail and other mail in the same mailbox. An attacker that can send mail to a user and can also observe the sizes of that user's IMAP traffic can...