Authentication Bypass Vulnerability in Dovecot by Open-Xchange
CVE-2026-24031

7.7HIGH

Key Information:

Vendor

Open-xchange Gmbh

Status
Ox Dovecot Pro
Vendor
CVE Published:
27 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-24031?

An authentication bypass vulnerability exists in Dovecot SQL authentication, where an administrator can inadvertently disable the 'auth_username_chars' configuration. This misconfiguration allows attackers to bypass authentication checks, potentially enabling unauthorized access and user enumeration. It is crucial for administrators to avoid clearing 'auth_username_chars'; if this cannot be prevented, they should promptly upgrade to the latest patched version to mitigate risks.

Affected Version(s)

OX Dovecot Pro 0 <= 3.1.0

OX Dovecot Pro 0 <= 2.4.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-24031
Created by aramosf

References

https://documentation.open-xchange.com/dovecot/security/a...
vendor-advisory

CVSS V3.1

Score:
7.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.