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 degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 01 Sep 2026 14:45:00 +0000

Type Values Removed Values Added
First Time appeared Open-xchange
Open-xchange ox Dovecot Ce
Open-xchange ox Dovecot Pro
Vendors & Products Open-xchange
Open-xchange ox Dovecot Ce
Open-xchange ox Dovecot Pro

Tue, 01 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Title Out‑Of‑Bounds Read in IMAP Hibernation Service Causes Crash dovecot: Dovecot: Denial of Service via malformed IMAP commands in imap-hibernate service
References
Metrics threat_severity

None

threat_severity

Moderate


Fri, 28 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 28 Aug 2026 14:00:00 +0000

Type Values Removed Values Added
Title Out‑Of‑Bounds Read in IMAP Hibernation Service Causes Crash

Fri, 28 Aug 2026 11:30:00 +0000

Type Values Removed Values Added
Description 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 degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: OX

Published:

Updated: 2026-08-28T15:03:07.769Z

Reserved: 2026-04-08T09:59:59.342Z

Link: CVE-2026-40015

cve-icon Vulnrichment

Updated: 2026-08-28T15:03:01.149Z

cve-icon NVD

Status : Received

Published: 2026-08-28T12:16:28.363

Modified: 2026-08-28T16:17:56.790

Link: CVE-2026-40015

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-28T10:12:18Z

Links: CVE-2026-40015 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-01T14:17:53Z

Weaknesses