Upstream information

CVE-2026-44687 at MITRE

Description

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).

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having moderate severity.

CVSS v3 Scores
CVSS detail CNA (NLnet Labs) SUSE
Base Score 3.7 3.7
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector Network Network
Attack Complexity High High
Privileges Required None None
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact None None
Integrity Impact None None
Availability Impact Low Low
CVSSv3 Version 3.1 3.1
CVSS v4 Scores
CVSS detail SUSE
Base Score 6.3
Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact Low
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0
SUSE Bugzilla entry: 1271893 [NEW]

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
openSUSE Tumbleweed
  • libunbound8 >= 1.25.2-1.1
  • python3-unbound >= 1.25.2-1.1
  • unbound >= 1.25.2-1.1
  • unbound-anchor >= 1.25.2-1.1
  • unbound-devel >= 1.25.2-1.1
  • unbound-munin >= 1.25.2-1.1
Patchnames:
openSUSE-Tumbleweed-2026-11380


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP7 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 unbound Affected
SUSE Linux Enterprise Micro 5.5 unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 unbound Affected
SUSE Linux Enterprise Module for Package Hub 15 SP7 unbound Affected
SUSE Linux Enterprise Server 15 SP7 unbound Affected
SUSE Linux Enterprise Server 16.0 unbound Affected
SUSE Linux Enterprise Server 16.1 unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 unbound Affected
SUSE Linux Enterprise Server for SAP applications 16.0 unbound Affected
SUSE Linux Enterprise Server for SAP applications 16.1 unbound Affected
SUSE Linux Micro 6.0 unbound Affected
SUSE Linux Micro 6.1 unbound Affected
SUSE Linux Micro 6.2 unbound Affected
openSUSE Leap 16.0 unbound Affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Performance Computing 15 SP4 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 unbound Affected
SUSE Linux Enterprise Server 15 SP4 unbound Affected
SUSE Linux Enterprise Server 15 SP4-LTSS unbound Affected
SUSE Linux Enterprise Server 15 SP5 unbound Affected
SUSE Linux Enterprise Server 15 SP5-LTSS unbound Affected
SUSE Linux Enterprise Server 15 SP6 unbound Affected
SUSE Linux Enterprise Server 15 SP6-LTSS unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 unbound Affected
SUSE Manager Proxy 4.3 unbound Affected
SUSE Manager Proxy LTS 4.3 unbound Affected
SUSE Manager Retail Branch Server 4.3 unbound Affected
SUSE Manager Retail Branch Server LTS 4.3 unbound Affected
SUSE Manager Server 4.3 unbound Affected
SUSE Manager Server LTS 4.3 unbound Affected
Products past their end of life and not receiving proactive updates anymore.
SUSE CaaS Platform 4.0 unbound Affected
SUSE Enterprise Storage 6 unbound Affected
SUSE Enterprise Storage 7 unbound Affected
SUSE Enterprise Storage 7.1 unbound Affected
SUSE Linux Enterprise Desktop 15 SP1 unbound Affected
SUSE Linux Enterprise Desktop 15 SP2 unbound Affected
SUSE Linux Enterprise Desktop 15 SP3 unbound Affected
SUSE Linux Enterprise Desktop 15 SP4 unbound Affected
SUSE Linux Enterprise Desktop 15 SP5 unbound Affected
SUSE Linux Enterprise Desktop 15 SP6 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP3 unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS unbound Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP1 unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP2 unbound Affected
SUSE Linux Enterprise Module for Basesystem 15 SP3 unbound Affected
SUSE Linux Enterprise Module for Package Hub 15 SP3 unbound Affected
SUSE Linux Enterprise Module for Package Hub 15 SP4 unbound Affected
SUSE Linux Enterprise Module for Package Hub 15 SP5 unbound Affected
SUSE Linux Enterprise Module for Package Hub 15 SP6 unbound Affected
SUSE Linux Enterprise Real Time 15 SP2 unbound Affected
SUSE Linux Enterprise Real Time 15 SP3 unbound Affected
SUSE Linux Enterprise Real Time 15 SP4 unbound Affected
SUSE Linux Enterprise Server 15 SP1 unbound Affected
SUSE Linux Enterprise Server 15 SP1-BCL unbound Affected
SUSE Linux Enterprise Server 15 SP1-LTSS unbound Affected
SUSE Linux Enterprise Server 15 SP2 unbound Affected
SUSE Linux Enterprise Server 15 SP2-BCL unbound Affected
SUSE Linux Enterprise Server 15 SP2-LTSS unbound Affected
SUSE Linux Enterprise Server 15 SP3 unbound Affected
SUSE Linux Enterprise Server 15 SP3-BCL unbound Affected
SUSE Linux Enterprise Server 15 SP3-LTSS unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 unbound Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 unbound Affected
SUSE Manager Proxy 4.0 unbound Affected
SUSE Manager Proxy 4.1 unbound Affected
SUSE Manager Proxy 4.2 unbound Affected
SUSE Manager Retail Branch Server 4.0 unbound Affected
SUSE Manager Retail Branch Server 4.1 unbound Affected
SUSE Manager Retail Branch Server 4.2 unbound Affected
SUSE Manager Server 4.0 unbound Affected
SUSE Manager Server 4.1 unbound Affected
SUSE Manager Server 4.2 unbound Affected
openSUSE Leap 15.3 unbound Affected
openSUSE Leap 15.4 unbound Affected
openSUSE Leap 15.5 unbound Affected
openSUSE Leap 15.6 unbound Affected


SUSE Timeline for this CVE

CVE page created: Thu Jul 23 11:35:40 2026
CVE page last modified: Mon Jul 27 12:03:36 2026