CVE Catalog

CVE-2026-78359

MediumCVSS 5.4
Published: Translated: NVD NIST

Summary

OTRS does not sufficiently enforce the uniqueness of customer user identities across multiple configured CustomerUser backends. When multiple backends (e.g., database and LDAP) are configured, the uniqueness check for customer user email addresses is performed only within the selected backend, allowing an authenticated user with permission to create or modify customer users to create a customer user whose email address is already assigned to a customer user in another backend. This can result in customer-related information or email communication being associated with or exposed to the wrong customer user. This affects versions 7.0.X, 8.0.X, 2023.X, 2024.X, 2025.X, 2026.X before 2026.7.X, and OTRS Community Edition 6.x and earlier.

Risk Assessment

An organization using OTRS may be exposed to incorrect association of information or email communication with the wrong customer user, potentially leading to data disclosure or errors in ticket handling. This requires permissions to create or modify customer users but can result in serious consequences for data confidentiality and integrity.

Recommendation

Update OTRS to version 2026.7.X or later, which fixes this vulnerability. Additionally, review the CustomerUser backend configuration and consider implementing additional email uniqueness checks at the application level.

Other vulnerabilities in OTRS

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Original NVD description (English source)

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

Vulnerability data from NVD (NIST) · CISA KEV · EPSS