CVE-2026-32934: Coredns.io Coredns

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-QUIC (DoQ) server can be driven into unbounded goroutine and memory growth by a remote client that opens many QUIC streams and sends only 1 byte per stream. When the worker pool is full, CoreDNS still spawns a goroutine per accepted stream to wait for a worker token. Additionally, active workers block indefinitely in io.ReadFull() with no per-stream read deadline, allowing an attacker to pin all workers by sending a single byte so the read blocks waiting for the second byte of the DoQ length prefix. This enables an unauthenticated remote attacker to cause memory exhaustion and OOM-kill. This issue has been fixed in version 1.14.3. No known workarounds exist.

Affected products

• Coredns.io Coredns: before 1.14.3 (fixed in 1.14.3)

Published 2026-05-05. Last modified 2026-07-25.