CVE-2026-32936 CoreDNS DoH GET path missing size validation causes CPU and memory amplification

CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-HTTPS DoH GET path accepts oversized dns= query parameter values and performs URL query parsing, base64 decoding, and DNS message unpacking before rejecting the request. Unlike the POST path, which applies a...

CVE-2026-32936

CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-HTTPS DoH GET path accepts oversized dns= query parameter values and performs URL query parsing, base64 decoding, and DNS message unpacking before rejecting the request. Unlike the POST path, which applies a...

CoreDNS DoH GET oversized dns= query parameter causes pre-validation CPU and memory amplification

Summary CoreDNS's DNS-over-HTTPS DoH GET path accepts oversized dns= query values and performs substantial request parsing, query unescaping, base64 decoding, and message unpacking work before returning 400 Bad Request. A remote, unauthenticated attacker can repeatedly send oversized DoH GET...