CVE-2026-78359
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.
Does this matter?
Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.
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
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- EPSS
- 0.16% probability · 6th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-694, CWE-706
- Source
- security@otrs.com
EPSS moved from 0.2% on 12 October 2026 to 0.2% on 26 October 2026.
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.