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3.7 Low

CVE-2026-40203 When IMAP compression is enabled, the same compression state is reused across responses in a session, so response…

Description

When IMAP compression is enabled, the same compression state is reused across responses in a session, so response sizes depend on both attacker-supplied mail and other mail in the same mailbox. An attacker that can send mail to a user and can also observe the sizes of that user's IMAP traffic can confirm whether the body of a small message matches a guessed text. Recovery of arbitrary unknown content was not demonstrated, but the attack can disclose whether a secret-like message body matches a candidate. Disable IMAP compression. Update to non-vulnerable version. No publicly available exploits are known.

Affected products and versions

Product Affected versions Fixed in
OX Dovecot Pro 3.1 3.1.0 → < 3.1.6 3.1.6
OX Dovecot Pro 3.0 3.0.0 → < 3.0.7 3.0.7
OX Dovecot Pro 2.3 2.3.0 → < 2.3.22.2 2.3.22.2
OX Dovecot CE 2.3 2.3.0 → < 2.4.5 2.4.5

References

Timeline

  1. Published
  2. Last modified

Other CVEs of OX Dovecot Pro

The 44 CVEs of OX Dovecot Pro →
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