DEBIAN-CVE-2026-81634

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Source
https://security-tracker.debian.org/tracker/CVE-2026-81634
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81634.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-81634
Upstream
  • CVE-2026-81634
Published
2026-09-16T09:17:06Z
Modified
2026-09-17T05:00:21Z
Severity
  • 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
Summary
[none]
Details

In NLnet Labs Unbound up to and including 1.26.0, a 255 length query name with a large TCP response can lead to a heap buffer overflow during the RRSet canonicalisation routine. This is caused by missing to add the first owner name into the buffer length check. A malicious actor operating a malicious name server or tampering with an incoming response to Unbound (canonicalisation happens before DNSSEC validation), can trigger the vulnerability.

References

Affected packages

Debian:12 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=bookworm

Affected ranges

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

Affected versions

1.*
1.17.1-2
1.17.1-2+deb12u1
1.17.1-2+deb12u2
1.17.1-2+deb12u3
1.17.1-2+deb12u4
1.17.1-2+loong64
1.18.0-1
1.18.0-2
1.19.1-1
1.19.2-1
1.20.0-1
1.21.1-1
1.22.0-1
1.22.0-2
1.23.1-1
1.24.0-1
1.24.0-2
1.24.1-1
1.24.1-2
1.24.2-1
1.25.0-1
1.25.1-1
1.25.2-1
1.26.0-1
1.26.0-2
1.26.1-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81634.json"

Debian:13 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=trixie

Affected ranges

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

Affected versions

1.*
1.22.0-2
1.22.0-2+deb13u1
1.22.0-2+deb13u2
1.22.0-2+deb13u3
1.23.1-1
1.24.0-1
1.24.0-2
1.24.1-1
1.24.1-2
1.24.2-1
1.25.0-1
1.25.1-1
1.25.2-1
1.26.0-1
1.26.0-2
1.26.1-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81634.json"

Debian:14 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=forky

Affected ranges

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

Affected versions

1.*
1.22.0-2
1.23.1-1
1.24.0-1
1.24.0-2
1.24.1-1
1.24.1-2
1.24.2-1
1.25.0-1
1.25.1-1
1.25.2-1
1.26.0-1
1.26.0-2
1.26.1-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81634.json"