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CVE-2026-78359

CVE-2026-78359 · Duplicate Identity / Identity Shadowing across CustomerUser backends

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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

CVSS 5.4 · Medium · EPSS 0.2%

Published
Updated

Stack: system

Affected products and versions

  • otrs

    Versions
    • 7.0.x: Affected
    • 8.0.x: Affected
    • 2023.x: Affected
    • 2024.x: Affected
    • 2025.x: Affected
    • ≥ 2026.x, ≤ 2026.6.x: Affected (patch)

    No fix published

  • ((otrs)) community edition

    Versions
    • 6.x: Affected

    No fix published

  • otrs2 Ubuntu:16.04:LTS

    Versions
    • 4.0.10-1
    • 5.0.1-1
    • 5.0.1-2
    • 5.0.2-1
    • 5.0.3-1
    • 5.0.5-1
    • 5.0.6-1
    • 5.0.7-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • otrs2 Ubuntu:18.04:LTS

    Versions
    • 5.0.23-1
    • 5.0.24-1
    • 6.0.1-1
    • 6.0.2-1
    • 6.0.3-1
    • 6.0.4-1
    • 6.0.5-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • otrs2 Ubuntu:20.04:LTS

    Versions
    • 6.0.20-1
    • 6.0.23-2
    • 6.0.24-1
    • 6.0.25-1
    • 6.0.25-2
    • 6.0.25-3
    • 6.0.26-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • otrs2 Ubuntu:22.04:LTS

    Versions
    • 6.0.32-6
    • 6.1.2-1
    • 6.2.1-1
    • 6.2.2-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • znuny Ubuntu:24.04:LTS

    Versions
    • 6.5.3-1
    • 6.5.4-1
    • 6.5.5-1
    • 6.5.6-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • znuny Ubuntu:26.10

    Versions
    • 6.5.18-1
    • 6.5.20-1
    • 6.5.21-1
    • 6.5.22-1
    • 6.5.23-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • znuny Ubuntu:26.04:LTS

    Versions
    • 6.5.15-2
    • 6.5.18-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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