Dovecot Auth Bypass via Clearing auth_username_chars (SQL Auth)
CVE-2026-24031 Published on March 27, 2026

Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-24031 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and a small impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
LOW

Weakness Type

What is a SQL Injection Vulnerability?

The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.

CVE-2026-24031 has been classified to as a SQL Injection vulnerability or weakness.


Products Associated with CVE-2026-24031

Want to know whenever a new CVE is published for Canonical Ubuntu Linux? stack.watch will email you.

 

Affected Versions

Open-Xchange GmbH OX Dovecot Pro:

Exploit Probability

EPSS
0.06%
Percentile
20.20%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.