CVE-2026-125393: MailEnable Enterprise Premium before 10.62 Heap Overflow via IMAP X-FB-FETCH
MailEnable Enterprise Premium before 10.62 contains a heap overflow vulnerability in the IMAP X-FB-FETCH command that allows authenticated users to overflow a fixed 0x400-byte heap buffer. Attackers can supply an X-FB-USER address longer than about 1016 bytes, which is formatted without a length check, to crash the IMAP service and cause denial of service.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MailEnable Enterprise Premiumto a version that resolves this vulnerability.Fixed in 10.62
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker needs valid authentication to the affected IMAP service. The available information does not indicate that unauthenticated users can trigger it.
What systems are affected?
MailEnable Enterprise Premium versions before 10.62 are affected. Exposure requires that the IMAP service accepts the X-FB-FETCH command from authenticated users.
What is required to trigger the denial of service?
The attacker sends an IMAP X-FB-FETCH request with an X-FB-USER address longer than approximately 1016 bytes. The unchecked value overflows a fixed 0x400-byte heap buffer and can crash the IMAP service.
What should be done if immediate patching is not possible?
Restrict IMAP access to trusted authenticated users where possible, since exploitation requires an authenticated account. Monitor the IMAP service for crashes or disruption consistent with malformed X-FB-FETCH requests.