VULNERABILITY INTELLIGENCE

CVE-2026-40014

CVSS score6.5 MEDIUM
EPSS probability0.33%
CISA KEVNot currently listed
Published2026-08-28
Last modified2026-09-03
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Description

An attacker that can send mail to a user can craft a message header that makes the IMAP THREAD command consume CPU disproportionate to the size of the message. When a mail client issues a THREAD command on the affected mailbox, this can cause degradation or denial of service for IMAP. Monitor system for abnormal CPU usage, kill the offending process and remove the offending message from the affected mailbox. Update to non-vulnerable version. No publicly available exploits are known.

Weakness classification

  • security@open-xchange.com: CWE-400

Primary references