otrs2, znuny — security advisory
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
- Products
- otrs2, znuny
- Affected versions
- 4.0.10-1, 5.0.1-1, 5.0.1-2, 5.0.2-1, 5.0.23-1, 5.0.24-1, 5.0.3-1, 5.0.5-1, 5.0.6-1, 5.0.7-1, 6.0.1-1, 6.0.2-1, 6.0.20-1, 6.0.23-2, 6.0.24-1, 6.0.25-1, 6.0.25-2, 6.0.25-3, 6.0.26-1, 6.0.3-1, 6.0.32-6, 6.0.4-1, 6.0.5-1, 6.1.2-1, 6.2.1-1, 6.2.2-2, 6.5.15-2, 6.5.18-1, 6.5.20-1, 6.5.21-1, 6.5.22-1, 6.5.23-1, 6.5.3-1, 6.5.4-1, 6.5.5-1, 6.5.6-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-78359
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:19 UTC · Revision 1
Source evidence
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
osv:UBUNTU-CVE-2026-78359
otrs2
Fixed versions: Not specified
otrs2
Fixed versions: Not specified
otrs2
Fixed versions: Not specified
otrs2
Fixed versions: Not specified
znuny
Fixed versions: Not specified
znuny
Fixed versions: Not specified
znuny
Fixed versions: Not specified
Complete source record
{
"id": "3259fce85b7a6d8a4a9574905d3f6105d5d823e57c83a082e430ab787c407a52",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-78359",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-78359",
"summary": "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",
"evidence": "osv:UBUNTU-CVE-2026-78359",
"products": [
{
"name": {
"value": "otrs2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.0.10-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.1-2",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.6-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.7-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.0.23-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.0.24-1",
"evidence": "/affected/1/versions"
},
{
"value": "6.0.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "6.0.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "6.0.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "6.0.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "6.0.5-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "otrs2",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.0.20-1",
"evidence": "/affected/2/versions"
},
{
"value": "6.0.23-2",
"evidence": "/affected/2/versions"
},
{
"value": "6.0.24-1",
"evidence": "/affected/2/versions"
},
{
"value": "6.0.25-1",
"evidence": "/affected/2/versions"
},
{
"value": "6.0.25-2",
"evidence": "/affected/2/versions"
},
{
"value": "6.0.25-3",
"evidence": "/affected/2/versions"
},
{
"value": "6.0.26-1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "otrs2",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.0.32-6",
"evidence": "/affected/3/versions"
},
{
"value": "6.1.2-1",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.1-1",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.2-2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "znuny",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.5.3-1",
"evidence": "/affected/4/versions"
},
{
"value": "6.5.4-1",
"evidence": "/affected/4/versions"
},
{
"value": "6.5.5-1",
"evidence": "/affected/4/versions"
},
{
"value": "6.5.6-1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "znuny",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.5.18-1",
"evidence": "/affected/5/versions"
},
{
"value": "6.5.20-1",
"evidence": "/affected/5/versions"
},
{
"value": "6.5.21-1",
"evidence": "/affected/5/versions"
},
{
"value": "6.5.22-1",
"evidence": "/affected/5/versions"
},
{
"value": "6.5.23-1",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "znuny",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.5.15-2",
"evidence": "/affected/6/versions"
},
{
"value": "6.5.18-1",
"evidence": "/affected/6/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-78359",
"aliases": [
"UBUNTU-CVE-2026-78359"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "otrs2",
"purl": "pkg:deb/ubuntu/otrs2?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"4.0.10-1",
"5.0.1-1",
"5.0.1-2",
"5.0.2-1",
"5.0.3-1",
"5.0.5-1",
"5.0.6-1",
"5.0.7-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "otrs",
"binary_version": "5.0.7-1"
},
{
"binary_name": "otrs2",
"binary_version": "5.0.7-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "otrs2",
"purl": "pkg:deb/ubuntu/otrs2?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"5.0.23-1",
"5.0.24-1",
"6.0.1-1",
"6.0.2-1",
"6.0.3-1",
"6.0.4-1",
"6.0.5-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "otrs",
"binary_version": "6.0.5-1"
},
{
"binary_name": "otrs2",
"binary_version": "6.0.5-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "otrs2",
"purl": "pkg:deb/ubuntu/otrs2?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"6.0.20-1",
"6.0.23-2",
"6.0.24-1",
"6.0.25-1",
"6.0.25-2",
"6.0.25-3",
"6.0.26-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "otrs",
"binary_version": "6.0.26-1"
},
{
"binary_name": "otrs2",
"binary_version": "6.0.26-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "otrs2",
"purl": "pkg:deb/ubuntu/otrs2?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"6.0.32-6",
"6.1.2-1",
"6.2.1-1",
"6.2.2-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
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{
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"binary_version": "6.2.2-2"
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},
{
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"events": [
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"package": {
"name": "znuny",
"purl": "pkg:deb/ubuntu/znuny?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"6.5.3-1",
"6.5.4-1",
"6.5.5-1",
"6.5.6-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "otrs2",
"binary_version": "6.5.6-1"
},
{
"binary_name": "znuny",
"binary_version": "6.5.6-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
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],
"package": {
"name": "znuny",
"purl": "pkg:deb/ubuntu/znuny?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"6.5.18-1",
"6.5.20-1",
"6.5.21-1",
"6.5.22-1",
"6.5.23-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "otrs2",
"binary_version": "6.5.23-1"
},
{
"binary_name": "znuny",
"binary_version": "6.5.23-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "znuny",
"purl": "pkg:deb/ubuntu/znuny?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"6.5.15-2",
"6.5.18-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-78359.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "otrs2",
"binary_version": "6.5.18-1"
},
{
"binary_name": "znuny",
"binary_version": "6.5.18-1"
}
]
}
}
],
"modified": "2026-10-17T13:01:08.740440922Z",
"provider": "osv",
"upstream": [
"CVE-2026-78359"
],
"references": [
"https://ubuntu.com/security/CVE-2026-78359",
"https://www.cve.org/CVERecord?id=CVE-2026-78359",
"https://otrs.com/release-notes/otrs-security-advisory-2026-16/"
]
},
"related_cves": [
{
"value": "CVE-2026-78359",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361066,
"published_at": "2026-10-12T07:16:00+00:00"
}