Description
NLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual domain-name operation but has no aggregate inbound decompression-work budget. Many chained compression pointers in a message results in a lot of CPU usage following them. A malicious actor with recursive-query access and control of an ordinarily delegated authority that serves specially crafted replies can exploit the vulnerability and degrade Unbound's general performance.
Published: 2026-10-21
Score: 5.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Solution

This issue is fixed starting with version 1.26.2

Tracking

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History

Wed, 21 Oct 2026 09:15:00 +0000

Type Values Removed Values Added
Description NLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual domain-name operation but has no aggregate inbound decompression-work budget. Many chained compression pointers in a message results in a lot of CPU usage following them. A malicious actor with recursive-query access and control of an ordinarily delegated authority that serves specially crafted replies can exploit the vulnerability and degrade Unbound's general performance.
Title Aggregate DNS name chained pointer decompression work leads to degradation of service.
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: NLnet Labs

Published:

Updated: 2026-10-21T08:57:26.986Z

Reserved: 2026-10-14T09:16:14.093Z

Link: CVE-2026-96405

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T09:17:08.357

Modified: 2026-10-21T09:17:08.357

Link: CVE-2026-96405

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling