What is CVE-2025-59028?

CVE-2025-59028 is a medium-severity vulnerability in Dovecot, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-03-27.

How severe is CVE-2025-59028?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Improper input validation in Dovecot

CVE-2025-59028

When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail. Invalid BASE64 data can be used to DoS a vulnerable server to break concurrent logins. Install f…

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.001 (25.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Dovecot
Open-xchange Dovecot
Open-xchange Gmbh Ox Dovecot Pro — versions 0

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

security@open-xchange.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2025-59028?: CVE-2025-59028 is a medium-severity vulnerability in Dovecot, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-03-27.
How severe is CVE-2025-59028?: Medium severity. CVSS v3 base score is 5.3 out of 10.