What is CVE-2026-12490?

CVE-2026-12490 is a high-severity vulnerability in Nlnet Labs Nsd, classified under Improper Access Control. CVSS score: 7.5/10. Published 2026-06-25.

How severe is CVE-2026-12490?

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

Auth bypass in Nlnet Labs Nsd

CVE-2026-12490

When a provide-xfr is given with a tls-auth-name, a secondary requesting a transfer should provide a client certificate with that name. However, no client certificate is needed when the request comes in over TLS over the regular tls-port (…

EPSS: 0.001 (3.5th percentile) — read the EPSS interpretation.

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:H/I:N/A:N.

Affected products

Nlnet Labs Nsd — versions 4.10.1
Nlnetlabs Nsd

Weakness classification (CWE)

CWE-284 — Improper Access Control
CWE-306 — Missing Authentication for Critical Function

References

sep@nlnetlabs.nl (vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-12490?: CVE-2026-12490 is a high-severity vulnerability in Nlnet Labs Nsd, classified under Improper Access Control. CVSS score: 7.5/10. Published 2026-06-25.
How severe is CVE-2026-12490?: High severity. CVSS v3 base score is 7.5 out of 10.