CVE-2026-32936: CoreDNS DoH GET path missing size validation causes CPU and memory amplification
Vulnerability summary
CVE-2026-32936 is a high (CVSS 8.7) Uncontrolled Resource Consumption vulnerability in coredns. EPSS estimates a 0.67% chance of exploitation in the next 30 days, higher than 52.1% of scored vulnerabilities. 1 public exploit is recorded.
Public exploit (GitHub, Date unknown)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1 · Related 2Timeline
- 05-05-2026PublishedVulnerability first disclosed.
- 05-05-2026Last modifiedVulnerability information updated.
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 metrics
7 scores · 5 sources · 2 versions- OSV · WolfiEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · GoEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- NVDNIST8.7HighCVSS: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:X/V:X/RE:X/U:X
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.67%
Chance of exploitation in the next 30 days
Percentile
52%
Versus all other CVEs
30-day change
Increase +0.06 pp
From 0.61% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
1 foundCoredns
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard22 products
- coredns-1.13All versions (No fix recorded)
- coredns-fips-1.13All versions (No fix recorded)
- eks-distro-coredns-1.30All versions (No fix recorded)
- eks-distro-coredns-1.31< 1.31.43-r2
- eks-distro-coredns-1.32< 1.32.36-r2
Wolfi5 products
- coredns-1.13All versions (No fix recorded)
- juicefs-1.3< 1.3.1-r14
- k8s_gateway< 1.8.0-r1
- kubernetes-dns-node-cache< 1.26.8-r3
- kuma-coredns-1.13All versions (No fix recorded)
Coredns1 product
- coredns< 1.14.3
Coredns.io1 product
- coredns< 1.14.3
Github.com/coredns1 product
- coredns< 1.14.3
5 vendors · 30 products
References
5 links- github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwrX Refsource CONFIRMAdvisoryWEBExploitMitigationVendor Advisory
- github.com/coredns/corednsPACKAGE