UBUNTU-CVE-2026-52686

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Source
https://ubuntu.com/security/CVE-2026-52686
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-52686
Upstream
Published
2026-07-23T09:16:00Z
Modified
2026-07-29T10:18:36Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

The issue is a DNSSEC validation bypass where wildcard expansion proofs (NSEC/NSEC3 records) are accepted without signature validation when the wildcard answer is a CNAME or DNAME record.

References

Affected packages

Ubuntu:24.04:LTS
pdns-recursor

Package

Name
pdns-recursor
Purl
pkg:deb/ubuntu/pdns-recursor?arch=source&distro=noble

Affected ranges

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

Affected versions

4.*
4.9.0-2
4.9.1-4
4.9.2-1
4.9.2-1build1
4.9.2-2
4.9.3-1
4.9.3-1build2
4.9.3-1build3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "pdns-recursor",
            "binary_version": "4.9.3-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json"
Ubuntu:26.04:LTS
pdns-recursor

Package

Name
pdns-recursor
Purl
pkg:deb/ubuntu/pdns-recursor?arch=source&distro=resolute

Affected ranges

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

Affected versions

5.*
5.2.4-2build2
5.3.1-1
5.3.3-1
5.3.4-1
5.3.4-1build1
5.3.4-2
5.3.5-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "pdns-recursor",
            "binary_version": "5.3.5-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json"
Ubuntu:Pro:16.04:LTS
pdns-recursor

Package

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

Affected ranges

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

Affected versions

3.*
3.7.3-1
4.*
4.0.0~alpha1-1
4.0.0~alpha1-2
4.0.0~alpha2-2
4.0.0~alpha2-2ubuntu0.1
4.0.0~alpha2-2ubuntu0.1+esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "pdns-recursor",
            "binary_version": "4.0.0~alpha2-2ubuntu0.1+esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json"
Ubuntu:Pro:18.04:LTS
pdns-recursor

Package

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

Affected ranges

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

Affected versions

4.*
4.0.6-1
4.0.6-1build1
4.0.7-1
4.1.1-1
4.1.1-1build1
4.1.1-2
4.1.1-2ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "pdns-recursor",
            "binary_version": "4.1.1-2ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json"
Ubuntu:Pro:20.04:LTS
pdns-recursor

Package

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

Affected ranges

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

Affected versions

4.*
4.2.0-6
4.2.1-1
4.2.1-1build1
4.2.1-1build2
4.2.1-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "pdns-recursor",
            "binary_version": "4.2.1-1ubuntu0.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json"
Ubuntu:Pro:22.04:LTS
pdns-recursor

Package

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

Affected ranges

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

Affected versions

4.*
4.4.2-3
4.6.0-1ubuntu1
4.6.0-1ubuntu1+esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "pdns-recursor",
            "binary_version": "4.6.0-1ubuntu1+esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52686.json"