SB2026040127 - Remote denial of service in Dovecot SASL implementation
Published: April 1, 2026
Security Bulletin ID
SB2026040127
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper input validation (CVE-ID: CVE-2025-59028)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 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
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.
Remediation
Install update from vendor's website.