UBUNTU-CVE-2026-93483

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Source
https://ubuntu.com/security/CVE-2026-93483
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-93483
Upstream
Published
2026-10-15T00:00:00Z
Modified
2026-10-17T13:01:17Z
Severity
  • 9.5 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/AU:Y/R:U/RE:L/U:Red CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this header, an attacker can impersonate any user, including administrators, without requiring a password. This grants full access to confidential data and system controls. More specifically, the HTTPBasicAuth modules for the agent (Kernel::System::Auth::HTTPBasicAuth) and customer (Kernel::System::CustomerAuth::HTTPBasicAuth) interfaces read the username to log in not only from $ENV{REMOTE_USER} (set by the web server after successful authentication), but also, as a fallback, from $ENV{HTTP_REMOTE_USER}, which is populated directly from an attacker-controllable "Remote-User" request header. On systems where HTTPBasicAuth was configured as the authentication backend, this allowed an attacker to log in as any existing user by sending a request with a forged Remote-User header, without providing any credentials.

References

Affected packages

Ubuntu:16.04:LTS
otrs2

Package

Name
otrs2
Purl
pkg:deb/ubuntu/otrs2?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

4.*
4.0.10-1
5.*
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

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs",
            "binary_version":  "5.0.7-1"
        },
        {
            "binary_name":  "otrs2",
            "binary_version":  "5.0.7-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"
Ubuntu:18.04:LTS
otrs2

Package

Name
otrs2
Purl
pkg:deb/ubuntu/otrs2?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

5.*
5.0.23-1
5.0.24-1
6.*
6.0.1-1
6.0.2-1
6.0.3-1
6.0.4-1
6.0.5-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs",
            "binary_version":  "6.0.5-1"
        },
        {
            "binary_name":  "otrs2",
            "binary_version":  "6.0.5-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"
Ubuntu:20.04:LTS
otrs2

Package

Name
otrs2
Purl
pkg:deb/ubuntu/otrs2?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

6.*
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

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs",
            "binary_version":  "6.0.26-1"
        },
        {
            "binary_name":  "otrs2",
            "binary_version":  "6.0.26-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"
Ubuntu:22.04:LTS
otrs2

Package

Name
otrs2
Purl
pkg:deb/ubuntu/otrs2?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.0.32-6
6.1.2-1
6.2.1-1
6.2.2-2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs2",
            "binary_version":  "6.2.2-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"
Ubuntu:24.04:LTS
znuny

Package

Name
znuny
Purl
pkg:deb/ubuntu/znuny?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.5.3-1
6.5.4-1
6.5.5-1
6.5.6-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs2",
            "binary_version":  "6.5.6-1"
        },
        {
            "binary_name":  "znuny",
            "binary_version":  "6.5.6-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"
Ubuntu:26.04:LTS
znuny

Package

Name
znuny
Purl
pkg:deb/ubuntu/znuny?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.5.15-2
6.5.18-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs2",
            "binary_version":  "6.5.18-1"
        },
        {
            "binary_name":  "znuny",
            "binary_version":  "6.5.18-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"
Ubuntu:26.10
znuny

Package

Name
znuny
Purl
pkg:deb/ubuntu/znuny?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

6.*
6.5.18-1
6.5.20-1
6.5.21-1
6.5.22-1
6.5.23-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "otrs2",
            "binary_version":  "6.5.23-1"
        },
        {
            "binary_name":  "znuny",
            "binary_version":  "6.5.23-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93483.json"