CVE-2026-32934: high-severity vulnerability in coredns
CoreDNS DNS-over-QUIC unbounded goroutine growth leads to denial of service
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.5%
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.
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
Affected products
coredns · corednsRelated CVEs — coredns
In the same product, most dangerous first.
CVE-2026-26018HIGHCoreDNS Loop Detection Denial of Service VulnerabilityEPSS 1.2%CVE-2025-47950HIGHCoreDNS Vulnerable to DoQ Memory Exhaustion via Stream AmplificationEPSS 1.2%CVE-2026-32936HIGHCoreDNS DoH GET path missing size validation causes CPU and memory amplificationEPSS 0.7%CVE-2026-62309HIGHCoreDNS: proxyproto plugin panics on PPv2 datagram with non-UDP transport — single 28-byte packet remote DoSEPSS 0.7%CVE-2026-35579HIGHCoreDNS TSIG authentication bypass on gRPC, QUIC, DoH, and DoH3 transportsEPSS 0.6%CVE-2026-82399HIGHCoreDNS: Unauthenticated memory exhaustion in custom transportsEPSS 0.6%