CVE-2026-27851: Dovecot

Critical severity, CVSS 9.1. EPSS: 0.6% chance of exploitation in the next 30 days.

When safe filter is used with variable expansion, all following pipelines on the same string are incorrectly interpreted as safe too, enabling unsafe data to be unescaped. This can enable SQL / LDAP injection attacks when used in authentication. Avoid using safe filter until on fixed version. No publicly available exploits are known.

Affected products

• Dovecot Dovecot: before 2.4.4 (fixed in 2.4.4)
• Open-Xchange Dovecot: before 3.1.5 (fixed in 3.1.5)

Published 2026-05-12. Last modified 2026-07-15.