CVE-2026-78359
Duplicate Identity / Identity Shadowing across CustomerUser backends
Published Oct 12, 2026 · corrected/updated Oct 15, 2026 · OTRS GmbH (former OTRS AG) OTRS · evidence confidence medium
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
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-78359 is a medium public vulnerability record for OTRS GmbH (former OTRS AG) OTRS. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether OTRS GmbH (former OTRS AG) OTRS is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: OTRS GmbH (former OTRS AG) ((OTRS)) Community Edition; OTRS GmbH (former OTRS AG) OTRS. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 5.4. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-694, CWE-706. Sources contributing to this record: circl, cve_org. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 12, 2026 · CIRCL Vulnerability Lookup
Detected
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 cu
Oct 15, 2026 · CIRCL Vulnerability Lookup
Updated
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 cu
Affected
- vendor OTRS GmbH (former OTRS AG) ((OTRS)) Community Editionversion unspecified
- vendor OTRS GmbH (former OTRS AG) OTRSversion unspecified
Sources
- CIRCL Vulnerability LookupVulnerability recordCVE-2026-78359
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
vulnerability.circl.lu - CVE.orgVulnerability recordCVE-2026-78359
Official CVE identifier
cve.org