What is CVE-2026-32665?

CVE-2026-32665 is a high-severity vulnerability in Nlnet Labs Unbound, classified under Improper Validation of Specified Quantity in Input. CVSS score: 7.5/10. Published 2026-07-22.

How severe is CVE-2026-32665?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Nlnet Labs Unbound

CVE-2026-32665

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, when downstream DNS-over-QUIC (DoQ) is enabled, the first two bidirectional streams on a new QUIC connection (stream_id 0 and 4) bypass the per-stream 'quic-size' gate entirely, and…

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Nlnet Labs Unbound — versions 1.22.0

Weakness classification (CWE)

CWE-1284 — Improper Validation of Specified Quantity in Input

References

sep@nlnetlabs.nl (vendor-advisory)

Frequently asked questions

What is CVE-2026-32665?: CVE-2026-32665 is a high-severity vulnerability in Nlnet Labs Unbound, classified under Improper Validation of Specified Quantity in Input. CVSS score: 7.5/10. Published 2026-07-22.
How severe is CVE-2026-32665?: High severity. CVSS v3 base score is 7.5 out of 10.