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Vulnerabilities

Vulnerability · CVE-2026-78359

Duplicate Identity / Identity Shadowing across CustomerUser backends

Published Oct 12, 2026 · catalog updated Oct 15, 2026 · OTRS GmbH (former OTRS AG) OTRS

Check if you run it

No confirmed exploitation is on record for CVE-2026-78359. EPSS is 0.16%. Act only if a listed version of OTRS GmbH (former OTRS AG) OTRS is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.16%
Remediation
Advisory link
Affected products
vendor OTRS GmbH (former OTRS AG) ((OTRS)) Community Edition · vendor OTRS GmbH (former OTRS AG) OTRS

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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor OTRS GmbH (former OTRS AG) ((OTRS)) Community Editionversion unspecified
  • vendor OTRS GmbH (former OTRS AG) OTRSversion unspecified

How to fix CVE-2026-78359

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-78359. EPSS is 0.16%. Act only if a listed version of OTRS GmbH (former OTRS AG) OTRS is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-694; CWE-706. EPSS 0.16%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

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.

  1. 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

  2. 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

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
  • FIRST EPSSExploitation probabilityCVE-2026-78359

    30-day exploitation probability 0.2%

    first.org

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.