CVE-2026-27860 | Open-Xchange OX Dovecot Pro up to 2.4.0/3.1.0 auth_username_chars ldap injection (adv-2026-0001)

VDB-353854 · CVE-2026-27860 · ADV-2026-0001 OPEN-XCHANGE OX DOVECOT PRO UP TO 2.4.0/3.1.0 AUTH_USERNAME_CHARS LDAP INJECTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 3.7 $0-$5k 2.88+ Summaryinfo A vulnerability was found in Open-Xchange OX Dovecot Pro up to 2.4.0/3.1.0 and classified as problematic. The affected element is an unknown function. Executing a manipulation of the argument auth_username_chars can lead to ldap injection. The identification of this vulnerability is CVE-2026-27860. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component. Detailsinfo A vulnerability classified as problematic was found in Open-Xchange OX Dovecot Pro up to 2.4.0/3.1.0. This vulnerability affects an unknown code. The manipulation of the argument auth_username_chars with an unknown input leads to a ldap injection vulnerability. The CWE definition for the vulnerability is CWE-90. The product constructs all or part of an LDAP query using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended LDAP query when it is sent to a downstream component. As an impact it is known to affect confidentiality. CVE summarizes: If auth_username_chars is empty, it is possible to inject arbitrary LDAP filter to Dovecot's LDAP authentication. This leads to potentially bypassing restrictions and allows probing of LDAP structure. Do not clear out auth_username_chars, or install fixed version. No publicly available exploits are known. The advisory is available at documentation.open-xchange.com. This vulnerability was named CVE-2026-27860 since 02/24/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1505 by the MITRE ATT&CK project. Upgrading eliminates this vulnerability. Productinfo Type Mail Server Software Vendor Open-Xchange Name OX Dovecot Pro Version 2.0 2.1 2.2 2.3 2.4.0 3.0 3.1.0 License open-source Website Vendor: https://www.open-xchange.com/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 3.7 VulDB Meta Temp Score: 3.7 VulDB Base Score: 3.7 VulDB Temp Score: 3.6 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 3.7 CNA Vector: 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Ldap injection CWE: CWE-90 / CWE-74 / CWE-707 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Timelineinfo 02/24/2026 CVE reserved 03/27/2026 +31 days Advisory disclosed 03/27/2026 +0 days VulDB entry created 03/27/2026 +0 days VulDB entry last update Sourcesinfo Vendor: open-xchange.com Advisory: adv-2026-0001 Status: Confirmed CVE: CVE-2026-27860 (🔒) GCVE (CVE): GCVE-0-2026-27860 GCVE (VulDB): GCVE-100-353854 Entryinfo Created: 03/27/2026 09:54 Changes: 03/27/2026 09:54 (63) Complete: 🔍 Cache ID: 99:CA3:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸