What is CVE-2026-96405?

CVE-2026-96405 is a medium-severity vulnerability in Nlnet Labs Unbound, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-10-21.

How severe is CVE-2026-96405?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Resource exhaustion in Nlnet Labs Unbound

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. 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.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Nlnet Labs Unbound

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

www.nlnetlabs.nl/downloads/unbound/CVE-2026-96405.txt (vendor-advisory)

Frequently asked questions

What is CVE-2026-96405?: CVE-2026-96405 is a medium-severity vulnerability in Nlnet Labs Unbound, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-10-21.
How severe is CVE-2026-96405?: Medium severity. CVSS v3 base score is 5.3 out of 10.