Duplicate Identity / Identity Shadowing across CustomerUser backends
Summary
| CVE | CVE-2026-78359 |
|---|---|
| State | PUBLISHED |
| Assigner | OTRS |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-12 07:16:37 UTC |
| Updated | 2026-10-12 07:16:37 UTC |
| Description | OTRS does not sufficiently enforce the uniqueness of customer user identities across multiple configured CustomerUser backends. When multiple backends, such as a database and LDAP, are configured, the uniqueness check for customer user email addresses is performed only within the selected backend. As a result, an authenticated user with permission to create or modify customer users may create a customer user whose email address is already assigned to a customer user in another backend. This can result in multiple customer user records representing the same communication identity. Depending on the affected workflow and backend resolution, customer-related information or email communication may subsequently be associated with or exposed to the wrong customer user. The vulnerability does not allow unauthenticated users to create customer accounts. Exploitation requires permissions to create or modify customer users. This issue affects OTRS: * 7.0.X * 8.0.X * 2023.X * 2024.X * 2025.X * 2026.X before 2026.7.X Please note that ((OTRS)) Community Edition 6.x and before are vulnerable. Products based on the ((OTRS)) Community Edition also very likely to be affected |
Risk And Classification
Primary CVSS: v3.1 5.4 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Problem Types: CWE-694 | CWE-706 | CWE-694 CWE-694 Use of Multiple Resources with Duplicate Identifier | CWE-706 CWE-706 Use of Incorrectly-Resolved Name or Reference
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | CNA | CVSS | 5.4 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | OTRS GmbH Former OTRS AG | OTRS | affected 7.0.x | Not specified |
| CNA | OTRS GmbH Former OTRS AG | OTRS | affected 8.0.x | Not specified |
| CNA | OTRS GmbH Former OTRS AG | OTRS | affected 2023.x | Not specified |
| CNA | OTRS GmbH Former OTRS AG | OTRS | affected 2024.x | Not specified |
| CNA | OTRS GmbH Former OTRS AG | OTRS | affected 2025.x | Not specified |
| CNA | OTRS GmbH Former OTRS AG | OTRS | affected 2026.x 2026.6.x patch | Not specified |
| CNA | OTRS GmbH Former OTRS AG | OTRS Community Edition | affected 6.x | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| otrs.com/release-notes/otrs-security-advisory-2026-16 | [email protected] | otrs.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Special thanks to Marc Hörsken for reporting this vulnerability (en)
Additional Advisory Data
Solutions
CNA: Update to latest version of OTRS (2026.7.1. or later). Please note that there will be no OTRS 7 patches
There are currently no legacy QID mappings associated with this CVE.