Vulnerability record · CVE-2026-32936 · published 5 May 2026
CVE-2026-32936: Coredns.io coredns uncontrolled resource consumption vulnerability
CCoredns.Io · Coredns
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.
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.
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/coredns/coredns/releases/tag/v1.14.3 | Release Notes |
| https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr | ExploitMitigationVendor Advisory |
| https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr | ExploitMitigationVendor Advisory |
Track CVE-2026-32936 inside VULONE
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-32936), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.