CVE-2026-33604 Affecting dovecot package, versions <2.4.5-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.27% (19th percentile)

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  • Snyk IDSNYK-ALPINE323-DOVECOT-19436018
  • published31 Aug 2026
  • disclosed28 Aug 2026

Introduced: 28 Aug 2026

NewCVE-2026-33604  (opens in a new tab)

How to fix?

Upgrade Alpine:3.23 dovecot to version 2.4.5-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dovecot package and not the dovecot package as distributed by Alpine. See How to fix? for Alpine:3.23 relevant fixed versions and status.

An attacker that can get Dovecot to relay a message, for example through Sieve redirect or submission relay, can use a crafted line ending in the message body to bypass the outbound protection that prevents message content from being interpreted as SMTP commands. A downstream mail server that hasn't yet fixed the SMTP smuggling vulnerability can be tricked into treating part of the message body as new SMTP commands, allowing injection of spoofed email. This is the same vulnerability class as CVE-2023-51764 and CVE-2023-51766. Where you control the receiving mail servers, ensure they reject bare carriage returns in message data. Update to non-vulnerable version. No publicly available exploits are known.

CVSS Base Scores

version 3.1