CVE-2026-32934 PUBLISHED

CoreDNS DNS-over-QUIC unbounded goroutine growth leads to denial of service

Assigner: GitHub_M
Reserved: 17.03.2026 Published: 05.05.2026 Updated: 05.05.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Product Status

Vendor coredns
Product coredns
Versions
  • Version < 1.14.3 is affected

References

Problem Types

  • CWE-770: Allocation of Resources Without Limits or Throttling CWE