CVE-2026-32936
Severity CVSS v4.0:
HIGH
Type:
CWE-400
Uncontrolled Resource Consumption ('Resource Exhaustion')
Publication date:
05/05/2026
Last modified:
05/05/2026
Description
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 bounded read via http.MaxBytesReader limited to 65536 bytes, the GET path has no equivalent size validation before expensive processing. A remote, unauthenticated attacker can repeatedly send oversized DoH GET requests to force high CPU usage, large transient memory allocations, and elevated garbage-collection pressure, leading to denial of service. This issue has been fixed in version 1.14.3.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH