CVE-2026-80225: Nlnetlabs Unbound

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

In NLnetLabs Unbound up to and including 1.26.0, a degradation of service vulnerability is present in the TCP/DoT reading procedure where there is no limit on consecutive reads. A malicious actor that can stream and sustain a rate of distinct uncached names over the TCP/DoT connection, monopolizes a single worker's entire event loop for as long as its writes stay ahead of the drain.

Affected products

• Nlnetlabs Unbound: before 1.26.1 (fixed in 1.26.1)

Published 2026-09-16. Last modified 2026-09-23.