UBUNTU-CVE-2026-19401

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Source
https://ubuntu.com/security/CVE-2026-19401
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-19401
Upstream
Published
2026-08-26T09:16:00Z
Modified
2026-09-10T11:01:19Z
Severity
  • 8.2 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.

References

Affected packages

Ubuntu:Pro:16.04:LTS
nsd

Package

Name
nsd
Purl
pkg:deb/ubuntu/nsd?arch=source&distro=esm-apps-legacy%2Fxenial

Affected ranges

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

Affected versions

4.*
4.1.2-1
4.1.6-1
4.1.7-1
4.1.7-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nsd",
            "binary_version": "4.1.7-1ubuntu0.1~esm1"
        },
        {
            "binary_name": "nsd3",
            "binary_version": "4.1.7-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json"
Ubuntu:Pro:18.04:LTS
nsd

Package

Name
nsd
Purl
pkg:deb/ubuntu/nsd?arch=source&distro=esm-apps%2Fbionic

Affected ranges

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

Affected versions

4.*
4.1.16-1build1
4.1.17-1
4.1.17-1build1
4.1.17-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nsd",
            "binary_version": "4.1.17-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json"
Ubuntu:Pro:20.04:LTS
nsd

Package

Name
nsd
Purl
pkg:deb/ubuntu/nsd?arch=source&distro=esm-apps%2Ffocal

Affected ranges

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

Affected versions

4.*
4.1.26-1
4.1.26-1build1
4.1.26-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nsd",
            "binary_version": "4.1.26-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json"
Ubuntu:Pro:22.04:LTS
nsd

Package

Name
nsd
Purl
pkg:deb/ubuntu/nsd?arch=source&distro=esm-apps%2Fjammy

Affected ranges

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

Affected versions

4.*
4.3.5-1
4.3.7-1
4.3.8-1
4.3.8-1build1
4.3.9-1
4.3.9-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nsd",
            "binary_version": "4.3.9-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json"
Ubuntu:Pro:24.04:LTS
nsd

Package

Name
nsd
Purl
pkg:deb/ubuntu/nsd?arch=source&distro=esm-apps%2Fnoble

Affected ranges

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

Affected versions

4.*
4.7.0-1
4.8.0-1
4.8.0-1build1
4.8.0-1build3
4.8.0-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nsd",
            "binary_version": "4.8.0-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json"
Ubuntu:Pro:26.04:LTS
nsd

Package

Name
nsd
Purl
pkg:deb/ubuntu/nsd?arch=source&distro=esm-apps%2Fresolute

Affected ranges

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

Affected versions

4.*
4.12.0-1
4.13.0-6
4.14.0-1
4.14.0-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "nsd",
            "binary_version": "4.14.0-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-19401.json"