CoreDNS up to 1.14.6 DNS-over-HTTPS plugin/pkg/doh/doh.go dns.Msg.Unpack allocation of resources

Summaryinfo

A vulnerability was found in CoreDNS up to 1.14.6 and classified as problematic. This impacts the function dns.Msg.Unpack of the file plugin/pkg/doh/doh.go of the component DNS-over-HTTPS. The manipulation results in allocation of resources. This vulnerability is cataloged as CVE-2026-82399. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in CoreDNS up to 1.14.6. Affected is the function dns.Msg.Unpack of the file plugin/pkg/doh/doh.go of the component DNS-over-HTTPS. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on availability. CVE summarizes:

CoreDNS is a DNS server written in Go. Prior to 1.14.7, the DNS-over-HTTPS, DNS-over-HTTP/3, DNS-over-QUIC, and DNS-over-gRPC request paths in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack on attacker-controlled DNS section counts before dns.DefaultMsgAcceptFunc validates the fixed header. An unauthenticated client can use DNS name compression and excessive section counts to amplify allocation before the plugin chain, so plugin-level rate limiting cannot prevent concurrent requests from exhausting memory and terminating CoreDNS. The ordinary UDP and TCP listeners are not affected because they validate the header first. This issue is fixed in version 1.14.7.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-82399 since 08/29/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 1.14.7 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• CoreDNS

Version

• 1.14.0
• 1.14.1
• 1.14.2
• 1.14.3
• 1.14.4
• 1.14.5
• 1.14.6

Website

• Product: https://github.com/coredns/coredns/

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