Security Flaw in CoreDNS Affects DNS-over-HTTPS and DNS-over-QUIC Services
CVE-2026-86003

7.5HIGH

Key Information:

Vendor

Coredns

Status
Coredns
Vendor
CVE Published:
16 September 2026

What is CVE-2026-86003?

CoreDNS, a widely used DNS server implementation in Go, features a vulnerability in its handling of DNS-over-HTTPS, DNS-over-HTTP/3, DNS-over-QUIC, and DNS-over-gRPC listeners. Prior to version 1.14.7, the server inadequately utilized request policies, allowing unauthenticated clients to exploit RFC 2136 UPDATE messages. This loophole can enable attackers to add, replace, or delete DNS records without proper validation if the upstream server accepts the spoofed requests from CoreDNS. Such unauthorized actions pose significant risks, including traffic redirection, DNS record alteration, and disruption of writable zones. The issue has been addressed in version 1.14.7.

Affected Version(s)

coredns < 1.14.7

References

https://github.com/coredns/coredns/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/coredns/coredns/commit/530b0a5ff2ad68c...
x_refsource_MISC
https://github.com/coredns/coredns/releases/tag/v1.14.7
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.