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Vulnerabilities

Vulnerability · CVE-2026-96405

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

Published Oct 21, 2026 · catalog updated Oct 22, 2026 · NLnet Labs Unbound up

Last checked Nov 6, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-96405. EPSS is 0.25%. Act only if a listed version of NLnet Labs Unbound up is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (NLnet Labs Unbound up).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.25%
Remediation
Advisory link
Affected products
Debian:12 unbound · Debian:13 unbound · Debian:14 unbound

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Debian:12 unbound1.17.1-2, 1.17.1-2+deb12u1, 1.17.1-2+deb12u2
  • Debian:13 unbound1.22.0-2, 1.22.0-2+deb13u1, 1.22.0-2+deb13u2
  • Debian:14 unbound1.22.0-2, 1.23.1-1, 1.24.0-1

How to fix CVE-2026-96405

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-96405. EPSS is 0.25%. Act only if a listed version of NLnet Labs Unbound up is installed.

Which versions are affected?

Compare what you have installed with 1.17.1-2, 1.17.1-2+deb12u1, 1.17.1-2+deb12u2, 1.22.0-2, 1.22.0-2+deb13u1, 1.22.0-2+deb13u2, 1.22.0-2, 1.23.1-1, 1.24.0-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-770: Allocation of Resources Without Limits or Throttling. EPSS 0.25%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2026 · NIST NVD

    Detected

    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 c

  2. Oct 22, 2026 · NIST NVD

    Updated

    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 c

Sources

  • CVE.orgVulnerability recordCVE-2026-96405

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-96405

    30-day exploitation probability 0.25%

    first.org
  • NIST NVDVulnerability recordCVE-2026-96405

    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

    nvd.nist.gov
  • Tenable CVE DatabaseVulnerability recordCVE-2026-96405

    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 c

    tenable.com
  • Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-96405

    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

    osv.dev

References

Freshness

Last verified in this catalog Nov 6, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 28, 2026
  • Trivy Vulnerability DBOct 23, 2026
  • Tenable CVE DatabaseOct 23, 2026
  • NIST NVDOct 22, 2026
  • CVE.orgOct 21, 2026