Upstream information
Description
NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the attack. An adversary that controls a DNSSEC signed zone can exploit this by signing NSEC3 records with acceptably high iterations for child delegations and querying a vulnerable Unbound. Unbound will keep performing the allowed hash calculations on the NSEC3 records and will not limit the work by the mitigation introduced in 1.19.1. As a side effect, a global lock for the negative cache will be held for the duration of the hashing, blocking other threads that need to consult the negative cache. Coordinated attacks could raise the vulnerability to denial of service. Unbound 1.25.1 contains a patch with a fix to bound the vulnerable code path with the existing limit for NSEC3 hash calculations.SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having moderate severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 5.9 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
| CVSS detail | CNA (NLnet Labs) |
|---|---|
| Base Score | 6.9 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber |
| Attack Vector | Network |
| Attack Complexity | Low |
| Attack Requirements | None |
| 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 |
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Please note that this evaluation state might be work in progress, incomplete or outdated.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: Tue May 19 10:30:55 2026CVE page last modified: Wed May 20 15:36:25 2026