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CVE-2026-33604

An attacker that can get Dovecot to relay a message, for example through Sieve redirect or submission relay, can use a crafted line ending i

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 2.3.22.2, 3.0.7, 3.1.6, 2.4.5
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • Open-Xchange GmbH OX Dovecot Pro

    From 2.3.0 · fixed in 2.3.22.2; From 3.0.0 · fixed in 3.0.7; From 3.1.0 · fixed in 3.1.6

  • Open-Xchange GmbH OX Dovecot CE

    From 2.3.0 · fixed in 2.4.5

References 1

documentation.open-xchange.com