← Vulnerability feed

Vulnerability record · CVE-2026-86003 · published 16 September 2026

CVE-2026-86003: CoreDNS is a DNS server written in Go.

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 listeners in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack without the dns.DefaultMsgAcceptFunc request policy used by UDP, TCP, and DNS-over-TLS. An unauthenticated client can send an RFC 2136 UPDATE that the proxy or forward plugin passes unchanged to an update-capable upstream. If that upstream trusts CoreDNS's source address or connection and does not require an attacker-unknown end-to-end TSIG, the request appears to originate from CoreDNS and can add, replace, or delete DNS records, redirect traffic, take over names, alter mail routing, or disrupt the writable zone. This issue is fixed in version 1.14.7.

7.5 CVSS 3.1 High EPSS 0.44% · top 64.6% CWE-441 · CWE-441 Awaiting Analysis
7.5CVSS 3.1 base score
0.44%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
3References
24 Sep 2026Last modified by NVD

Description

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 listeners in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack without the dns.DefaultMsgAcceptFunc request policy used by UDP, TCP, and DNS-over-TLS. An unauthenticated client can send an RFC 2136 UPDATE that the proxy or forward plugin passes unchanged to an update-capable upstream. If that upstream trusts CoreDNS's source address or connection and does not require an attacker-unknown end-to-end TSIG, the request appears to originate from CoreDNS and can add, replace, or delete DNS records, redirect traffic, take over names, alter mail routing, or disrupt the writable zone. This issue is fixed in version 1.14.7.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

LinkTags
https://github.com/coredns/coredns/commit/530b0a5ff2ad68cc0421f10dd93568945cc671c9
https://github.com/coredns/coredns/releases/tag/v1.14.7
https://github.com/coredns/coredns/security/advisories/GHSA-9gm5-9rfh-m6vx

Track CVE-2026-86003 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2026-83548SonicWall SMA1000 pre-auth SSRF via alternate access pathThe SMA1000 Appliance Work Place interface exposes an unintended alternate access path that allows server-side request forgery before authentication.…KEVEPSS 8.8%analysed

Source: NIST National Vulnerability Database (record CVE-2026-86003), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.