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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-2wpx-qpw2-g5h5 CoreDNS' DoQ worker pool does not bound stream backlog
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 05 May 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Coredns.io
Coredns.io coredns
Vendors & Products Coredns.io
Coredns.io coredns

Tue, 05 May 2026 19:30:00 +0000

Type Values Removed Values Added
Description 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.
Title CoreDNS DNS-over-QUIC unbounded goroutine growth leads to denial of service
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 8.7, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-05T19:06:17.080Z

Reserved: 2026-03-17T00:05:53.282Z

Link: CVE-2026-32934

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-05T20:16:35.853

Modified: 2026-05-05T20:16:35.853

Link: CVE-2026-32934

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-05T21:30:05Z

Weaknesses