CVE-2026-42391 Affecting dovecot-mysql package, versions <1:2.3.16-18.el9_8.8


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.45% (37th percentile)

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  • Snyk IDSNYK-ORACLE9-DOVECOTMYSQL-20840548
  • published12 Oct 2026
  • disclosed28 Aug 2026

Introduced: 28 Aug 2026

CVE-2026-42391  (opens in a new tab)

How to fix?

Upgrade Oracle:9 dovecot-mysql to version 1:2.3.16-18.el9_8.8 or higher.
This issue was patched in ELSA-2026-80825.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dovecot-mysql package and not the dovecot-mysql package as distributed by Oracle. See How to fix? for Oracle:9 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1