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CVE PROGRAM SOURCE RECORD7.5 High

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

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Status
Published
Published
Updated
Assigning organization
OX

Description

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 the same process. This can cause degradation or denial of service for IMAP logins. Limit the number of connections handled by a single imap-login process. This has a performance impact though. Update to non-vulnerable version. No publicly available exploits are known.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Open-Xchange GmbH OX Dovecot Pro

Default version status: unaffected

  • 2.3.0 to < 2.3.22.2affected
  • 3.0.0 to < 3.0.7affected
  • 3.1.0 to < 3.1.6affected

Open-Xchange GmbH OX Dovecot CE

Default version status: unaffected

  • 2.3.0 to < 2.4.5affected

References