DEBIAN-CVE-2026-44687

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Source
https://security-tracker.debian.org/tracker/CVE-2026-44687
Import Source
https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44687.json
JSON Data
https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2026-44687
Upstream
Published
2026-07-22T14:17:19Z
Modified
2026-09-19T16:00:08Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
[none]
Details

In NLnet Labs Unbound 1.13.2 up to and including 1.25.1, stub or forward zones where the name is below an intermediate labed below a DNSSEC signed zone could be shadowed by the intermediate label's secure NXDOMAIN answer from the parent. This is caused by an off-by-one error in 'harden-below-nxdomain' logic; enabled by default. It effectively bypasses the configuration and the configured stub/forward zone is never contacted. 'harden-below-nxdomain' does an upward DNS cache walk together with a delegation point guard that does not allow NXDOMAIN synthesis above stub/forward zones. The guard tests the domain name but before stripping a label. This results in an iteration where the domain name equals the configured stub/forward zone apex that passes the guard, strips one more label, and probes the cache at the apex's immediate public parent. If that parent has a cached DNSSEC-secure NXDOMAIN, which it will for any private namespace nested two or more labels under a signed public name, the walk returns it and the configured stub/forward upstream is never contacted. This can only be triggered by the query for the intermediate label (between the stub/forward apex and the DNSSEC parent zone).

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/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44687.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
Fixed
1.26.1-0+deb13u1

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

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44687.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
Fixed
1.25.2-1

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

Ecosystem specific 

{
    "urgency":  "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44687.json"