CVE catalog
CVE-2026-44687
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 se
- Severity
- Low · CVSS 3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.22% · Oct 25, 2026
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).
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | unbound | sid | 1.26.2-1 | fixed |
| Debian | unbound | forky | 1.26.2-1 | fixed |
| Debian | unbound | trixie | 1.22.0-2+deb13u3 | vulnerable |
| Debian | unbound | trixie-security | 1.26.2-0+deb13u1 | fixed |
| Debian | unbound | bookworm | 1.17.1-2+deb12u4 | vulnerable |
| Debian | unbound | bookworm-security | 1.17.1-2+deb12u3 | vulnerable |
| Alpine | unbound | 3.22 | 1.25.2-r0 | fixed |
| Alpine | unbound | 3.23 | 1.25.2-r0 | fixed |
| Alpine | unbound | 3.24 | 1.25.2-r0 | fixed |
| Ubuntu | unbound | pro | 1.9.0-2ubuntu1 | vulnerable |
| Ubuntu | unbound | pro | 1.9.0-2ubuntu2 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.1 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.2 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.3 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.4 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.5 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.6 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.8 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.9 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.11 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.11+esm1 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.11+esm2 | vulnerable |
| Ubuntu | unbound | pro | 1.9.4-2ubuntu1.11+esm3 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu3 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.1 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.2 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.3 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.4 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.5 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.7 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.8 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.10 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.11 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.12 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.13 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.14 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.15 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.16 | vulnerable |
| Ubuntu | unbound | 22.04 | 1.13.1-1ubuntu5.17 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.17.1-2 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.18.0-2ubuntu1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.18.0-2ubuntu2 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.1-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.1 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.2 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.3 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.4 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.5 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.6 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.7 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.8 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.9 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.10 | vulnerable |
| Ubuntu | unbound | 24.04 | 1.19.2-1ubuntu3.12 | vulnerable |
| Ubuntu | unbound | 26.10 | 1.24.2-1ubuntu2 | vulnerable |
| Ubuntu | unbound | 26.10 | 1.25.1-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 26.10 | 1.25.1-1ubuntu3 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.22.0-2ubuntu2 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.22.0-2ubuntu4 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu1 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2.1 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2.2 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2.3 | vulnerable |
| Ubuntu | unbound | 26.04 | 1.24.2-1ubuntu2.4 | vulnerable |
| Cpe | unbound | Not reported | 1.25.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | unbound | source | sid | 1.25.2-1 | not yet assigned | Not reported | Not reported |
| Debian | unbound | source | forky | 1.25.2-1 | not yet assigned | Not reported | Not reported |
| Debian | unbound | source | trixie | 1.26.1-0+deb13u1 | not yet assigned | Not reported | Not reported |
| Debian | unbound | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
| Alpine | unbound | apk | 3.22 | 1.25.2-r0 | Not reported | ALPINE-CVE-2026-44687 | Not reported |
| Alpine | unbound | apk | 3.23 | 1.25.2-r0 | Not reported | ALPINE-CVE-2026-44687 | Not reported |
| Alpine | unbound | apk | 3.24 | 1.25.2-r0 | Not reported | ALPINE-CVE-2026-44687 | Not reported |
| Cpe | unbound | cpe | Not reported | 1.25.2 | Not reported | NVD-CVE-2026-44687 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libunbound8]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [libunbound-dev]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [python3-unbound]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [unbound]Affected
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [unbound-anchor]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
- [unbound-host]Affected
Source package: [unbound]
Details (4)
1.17.1-2+deb12u4· amd64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u4· arm64 · bookwormAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· amd64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
1.17.1-2+deb12u3· arm64 · bookworm-securityAffected
nvd · unbound · debian · bookworm; nvd · unbound · debian · 12
[Debian 13 (Trixie)]
- [libunbound8]Affected
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
- [libunbound-dev]Affected
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
- [python3-unbound]Affected
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
- [unbound]Affected
Details (6)
1.22.0-2+deb13u3· amd64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
- [unbound-anchor]Affected
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
- [unbound-host]Affected
Source package: [unbound]
Details (6)
1.22.0-2+deb13u3· amd64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixieAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· amd64 · trixie-security · Historical versionAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.22.0-2+deb13u3· arm64 · trixie-securityAffected · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.1-0+deb13u1· amd64 · trixie-security · Historical versionFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
1.26.2-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.26.1-0+deb13u1nvd · unbound · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11380-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-44687]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-44687]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-44687]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-44687]
- [https://security-tracker.debian.org/tracker/CVE-2026-44687]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44687.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-3038.json]
- [https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-44687.txt]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]