Improper input validation in Dovecot and OX Dovecot Pro - CVE-2025-59028

 

Improper input validation in Dovecot and OX Dovecot Pro - CVE-2025-59028

Published: April 1, 2026


Vulnerability identifier: #VU124721
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-59028
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability: No public exploit available
Vendor: Dovecot
Affected software:
Dovecot
OX Dovecot Pro

Detailed vulnerability description

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper input validation in SASL authentication handling when processing user-supplied data. A remote attacker can send a specially crafted request containing invalid base64 data to cause a denial of service.

The denial of service affects concurrent authentication sessions.


How to mitigate CVE-2025-59028

Install security update from vendor's website.

Sources