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CVE-2026-78359

Status: DeferredMedium (5.4)—
Severity5.4Medium · CVSS 3.1
Exploitation probability0.16 %higher than 5% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

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.

Read full descriptionShow less

The vulnerability does not allow unauthenticated users to create customer accounts. Exploitation requires permissions to create or modify customer users.

This issue affects OTRS:

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

Technical details traces, logs and code from the original report
  *  7.0.X
  *  8.0.X
  *  2023.X
  *  2024.X
  *  2025.X
  *  2026.X before 2026.7.X

CVSS

Base score
5.4
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.16 %
Percentile among all scored CVEs
5
Score date
10/24/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

Acceso autenticado a servicio remoto (OTRS) con PR:L permite crear identidades fraudulentas de clientes. Consecuencias: escalada de privilegios funcionales (T1078.003 account manipulation), manipulación de datos de clientes y exposición de comunicaciones (T1565.003, T1552.007).

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Privileged Account ManagementNetwork SegmentationUser Account ManagementVulnerability ScanningThreat Intelligence ProgramRestrict File and Directory Permissions

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Otrs — OtrsAI

CWEs

References

Show 1 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-78359",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-78359",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-15T16:41:22.839568Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security@otrs.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.4,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.5,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "security@otrs.com",
      "affectedData": [
        {
          "vendor": "OTRS GmbH (former OTRS AG)",
          "product": "OTRS",
          "versions": [
            {
              "status": "affected",
              "version": "7.0.x"
            },
            {
              "status": "affected",
              "version": "8.0.x"
            },
            {
              "status": "affected",
              "version": "2023.x"
            },
            {
              "status": "affected",
              "version": "2024.x"
            },
            {
              "status": "affected",
              "version": "2025.x"
            },
            {
              "status": "affected",
              "version": "2026.x",
              "versionType": "patch",
              "lessThanOrEqual": "2026.6.x"
            }
          ],
          "defaultStatus": "unaffected"
        },
        {
          "vendor": "OTRS GmbH (former OTRS AG)",
          "product": "((OTRS)) Community Edition",
          "versions": [
            {
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              "version": "6.x"
            }
          ],
          "defaultStatus": "affected"
        }
      ]
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  ],
  "published": "2026-10-12T07:16:37.423",
  "references": [
    {
      "url": "https://otrs.com/release-notes/otrs-security-advisory-2026-16/",
      "source": "security@otrs.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security@otrs.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-694"
        },
        {
          "lang": "en",
          "value": "CWE-706"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "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.\n\nThis 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.\n\nThe vulnerability does not allow unauthenticated users to create customer accounts. Exploitation requires permissions to create or modify customer users.\n\nThis issue affects OTRS:\n\n  *  7.0.X\n  *  8.0.X\n  *  2023.X\n  *  2024.X\n  *  2025.X\n  *  2026.X before 2026.7.X\n\nPlease note that ((OTRS)) Community Edition 6.x and before are vulnerable. Products based on the ((OTRS)) Community Edition also very likely to be affected"
    }
  ],
  "lastModified": "2026-10-15T20:38:44.050",
  "sourceIdentifier": "security@otrs.com"
}