((Otrs)) Community Edition

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

Published: 2026-10-12T06:49:24.983Z
Updated: 2026-10-15T19:15:00.046Z

Several administrative actions do not sufficiently validate whether a request was intentionally initiated by the authenticated user. In particular, the DBUpdateLogCleanUp action can be triggered through a GET request without validating a ChallengeToken. An unauthenticated remote attacker can therefore cause the browser of an authenticated administrator to execute the cleanup action by embedding a crafted request in a malicious web page. Successful exploitation can delete existing DBUpdate log entries. This may reduce the availability of diagnostic and historical information used for troubleshooting and auditing. The impact is limited to DBUpdate log entries that exist at the time the forged request is processed. Additional administrative endpoints were identified that do not validate a ChallengeToken. Some of these endpoints can trigger administrative actions such as deploying or synchronizing already existing configuration. They do not allow an attacker to introduce arbitrary new configuration through the CSRF request itself.  Export and read-only endpoints were also identified without ChallengeToken validation. While these endpoints may be triggered through a forged cross-site request, the response content remains subject to the browser's same-origin restrictions and is not automatically exposed to the attacker. Therefore, no direct confidentiality impact has been demonstrated for these endpoints. 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

Published: 2026-10-12T06:49:18.716Z
Updated: 2026-10-15T19:15:00.236Z

User-controlled values are not sufficiently neutralized when included in CSV exports. Values originating from user input, including data submitted by authenticated users or received through external communication channels such as email, may be stored in fields that are later included in CSV exports. An attacker can therefore inject values beginning with spreadsheet formula characters such as =, +, -, or @. An attacker does not necessarily require an authenticated account if the affected field can be populated through an external input channel such as incoming email. When an affected CSV file is opened in spreadsheet software, the application may interpret these values as formulas instead of plain text. Depending on the spreadsheet application and its security configuration, a malicious formula may cause unintended actions, disclose information, or invoke external functionality. Exploitation may require the user opening the exported CSV file to confirm one or more security warning dialogs. The vulnerability does not execute code on the OTRS server; any additional impact occurs in the spreadsheet application used to process the exported file. 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

Published: 2026-10-12T06:49:31.279Z
Updated: 2026-10-15T19:14:59.884Z

The HTTP Basic Authentication modules in ((OTRS)) Community Edition 6 and prior accept the authenticated username from either the REMOTE_USER or HTTP_REMOTE_USER environment variable. In CGI and mod_perl based deployments, HTTP request headers may be mapped to corresponding HTTP_* environment variables. As a result, an unauthenticated remote attacker can supply a crafted Remote-User request header which is exposed to the application as HTTP_REMOTE_USER. When HTTP Basic Authentication is configured as the authentication backend, OTRS trusts this value as an already authenticated username and does not perform an additional password verification. An attacker may therefore authenticate through the Generic Interface as an existing agent or customer user without knowing the corresponding credentials. The resulting privileges depend on the account being impersonated. Successful exploitation may allow access to confidential information and modification of data or configuration with the permissions of the affected user. Exploitation requires HTTP Basic Authentication to be configured as an authentication backend and a web server environment in which attacker-controlled HTTP headers are exposed through the corresponding HTTP_* environment variables. OTRS 7 and later are not affected by this attack vector due to the use of Mojolicious/Hypnotoad and does not expose arbitrary request headers through %ENV in the manner required for exploitation. The supported REMOTE_USER mechanism additionally requires validation through the configured SSO shared secret. The unused HTTP_REMOTE_USER fallback has nevertheless been removed as a security-hardening measure. 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

Published: 2026-10-12T06:49:38.903Z
Updated: 2026-10-15T19:14:59.764Z