CVE-2026-55991

Vendor

Microsoft

Product

dnsmasq / Unbound / PowerDNS

CVSS

5.9

Exposure class

Edge / VPN / firewall

Every item in the archive that references this CVE, highest rank first. Headlines open the publisher.

1. 15
   CVE NVD 22 Jul 2026

   In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a remote unauthenticated client can trigger a libngtcp2 assertion (if compiled with…

   In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a remote unauthenticated client can trigger a libngtcp2 assertion (if compiled with assertions on) and terminate the entire Unbound process using a single DNS-over-QUIC…

   CVSS 5.9 CVE-2026-55991
2. 8
   Advisory MSRC 23 Jul 2026

   CVE-2026-55991 Remote DNS-over-QUIC (DoQ) flow-control assertion failure in libngtcp2

   Information published.

   CVE-2026-55991 Microsoft