Vulnerability · Published May 5, 2026 · Assigned by GitHub_M
CVE-2026-32934CoreDNS DNS-over-QUIC unbounded goroutine growth leads to denial of service
High 8.7
In plain English
A high-severity resource allocation without limits in coredns from coredns. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/coredns/coredns | 1.14.3 | GHSA-2wpx-qpw2-g5h5 |
| Go | github.com/coredns/coredns | 1.14.3 | GO-2026-4969 |
Affected products (as reported)
Weakness: CWE-770 · 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
References
- https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5 x_refsource_CONFIRM
- https://github.com/coredns/coredns/releases/tag/v1.14.3 x_refsource_MISC