Vulnerability in Nlnet Labs Unbound
CVE-2026-44390
NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability when handling replies with very large RRsets that Unbound needs to perform name compression for. Malicious upstream responses with very large RRsets with records tha…
EPSS: 0.006 (42.7th percentile) — read the EPSS interpretation.
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.
Affected products
- Nlnet Labs Unbound — versions 0
- Nlnetlabs Unbound
Weakness classification (CWE)
References
- sep@nlnetlabs.nl (vendor-advisory, Mitigation, Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-44390?
- CVE-2026-44390 is a medium-severity vulnerability in Nlnet Labs Unbound, classified under Inefficient Algorithmic Complexity. CVSS score: 5.3/10. Published 2026-05-20.
- How severe is CVE-2026-44390?
- Medium severity. CVSS v3 base score is 5.3 out of 10.