UBUNTU-CVE-2026-43966

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Source
https://ubuntu.com/security/CVE-2026-43966
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-43966
Upstream
Withdrawn
2026-06-19T15:57:11Z
Published
2026-06-15T00:00:00Z
Modified
2026-06-19T18:00:07.973575083Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') vulnerability in ninenines cowlib allows HTTP response splitting via non-VCHAR bytes in structured-fields string values. cowhttpstructhd:escapestring/2 in cowlib only escapes \ and ", passing all other bytes through verbatim. This creates an encoder/decoder asymmetry: the matching parser accepts only printable ASCII (0x20–0x7E, excluding " and ), but the encoder emits any byte including CR and LF. An application that builds a structured HTTP header via cowhttpstructhd:item/1 (or a higher-level wrapper such as cowhttphd:wtprotocol/1) from attacker-controlled input can have \r\n injected into the serialized header value. Once on the wire, the injected CRLF terminates the current header and any following bytes are interpreted as a new header, enabling HTTP response splitting. This issue affects cowlib from 2.9.0.

References

Affected packages

Ubuntu:18.04:LTS
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=bionic

Affected ranges

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

Affected versions

3.*
3.6.10-1
3.6.10-1ubuntu0.1
3.6.10-1ubuntu0.3
3.6.10-1ubuntu0.4
3.6.10-1ubuntu0.5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.6.10-1ubuntu0.5",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"
Ubuntu:20.04:LTS
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=focal

Affected ranges

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

Affected versions

3.*
3.7.8-4ubuntu2
3.7.18-1
3.8.2-0ubuntu1
3.8.2-0ubuntu1.1
3.8.2-0ubuntu1.2
3.8.2-0ubuntu1.3
3.8.2-0ubuntu1.4
3.8.2-0ubuntu1.5
3.8.3-0ubuntu0.1
3.8.3-0ubuntu0.2
3.8.3-0ubuntu0.3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.8.3-0ubuntu0.3",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"
Ubuntu:22.04:LTS
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=jammy

Affected ranges

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

Affected versions

3.*
3.8.9-3ubuntu1
3.9.8-1
3.9.8-2
3.9.8-3
3.9.8-5
3.9.8-6
3.9.13-1
3.9.13-1ubuntu0.22.04.1
3.9.13-1ubuntu0.22.04.2
3.9.27-0ubuntu0.1
3.9.27-0ubuntu0.2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.9.27-0ubuntu0.2",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"
Ubuntu:24.04:LTS
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=noble

Affected ranges

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

Affected versions

3.*
3.12.1-1
3.12.1-1ubuntu1
3.12.1-1ubuntu1.2
3.12.1-1ubuntu1.4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.12.1-1ubuntu1.4",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"
Ubuntu:25.10
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=questing

Affected ranges

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

Affected versions

4.*
4.0.5-2ubuntu2
4.0.5-6ubuntu1
4.0.5-8ubuntu1
4.0.5-8ubuntu2
4.0.5-8ubuntu2.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "4.0.5-8ubuntu2.1",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"
Ubuntu:26.04:LTS
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=resolute

Affected ranges

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

Affected versions

4.*
4.0.5-8ubuntu2
4.0.5-10ubuntu1
4.0.5-10ubuntu2
4.0.5-10ubuntu3
4.0.5-10ubuntu4
4.0.5-10ubuntu5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "4.0.5-10ubuntu5",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"
Ubuntu:Pro:16.04:LTS
rabbitmq-server

Package

Name
rabbitmq-server
Purl
pkg:deb/ubuntu/rabbitmq-server?arch=source&distro=esm-infra%2Fxenial

Affected ranges

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

Affected versions

3.*
3.5.4-1
3.5.4-3
3.5.4-3.1
3.5.7-1
3.5.7-1ubuntu0.16.04.1
3.5.7-1ubuntu0.16.04.2
3.5.7-1ubuntu0.16.04.4
3.5.7-1ubuntu0.16.04.4+esm1
3.5.7-1ubuntu0.16.04.4+esm2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.5.7-1ubuntu0.16.04.4+esm2",
            "binary_name": "rabbitmq-server"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-43966.json"