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Vulnerability record · CVE-2026-33190 · published 5 May 2026

CVE-2026-33190: Coredns.io coredns vulnerability

CCoredns.Io · Coredns

CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer's TsigStatus() instead of performing verification itself. The DoH and DoH3 writer's TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.

8.7 CVSS 4.0 High EPSS 0.53% · top 57.8% CWE-303 · CWE-303
8.7CVSS 4.0 base score
0.53%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References, 2 tagged exploit
24 Jul 2026Last modified by NVD

Description

CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer's TsigStatus() instead of performing verification itself. The DoH and DoH3 writer's TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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

LinkTags
https://github.com/coredns/coredns/releases/tag/v1.14.3 Release Notes
https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh ExploitVendor Advisory
https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh ExploitVendor Advisory

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Related vulnerabilities

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

8.7CVE-2026-32936Coredns.io coredns uncontrolled resource consumption vulnerabilityCoreDNS 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 va…EPSS 0.61%8.7CVE-2026-32934Coredns.io coredns allocation without limits vulnerabilityCoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-QUIC (DoQ) server can be driven into unbounded goroutine and m…EPSS 0.63%8.2CVE-2026-35579Coredns.io coredns improper authentication vulnerabilityCoreDNS is a DNS server written in Go. In versions prior to 1.14.3, the gRPC, QUIC, DoH, and DoH3 transport implementations incorrectly handle TSIG a…EPSS 0.75%8.2CVE-2026-33489Coredns.io coredns incorrect authorization vulnerabilityCoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone…EPSS 0.42%7.5CVE-2026-62309Coredns.io coredns null pointer dereference vulnerabilityCoreDNS is a DNS server written in Go. Prior to 1.14.4, a single 28-byte UDP datagram can crash the CoreDNS process when the proxyproto plugin is ena…EPSS 0.66%7.5CVE-2026-26018Coredns.io coredns uncontrolled resource consumption vulnerabilityCoreDNS is a DNS server that chains plugins. Prior to version 1.14.2, a denial of service vulnerability exists in CoreDNS's loop detection plugin tha…EPSS 0.76%7.5CVE-2025-47950Coredns.io coredns allocation without limits vulnerabilityCoreDNS is a DNS server that chains plugins. In versions prior to 1.12.2, a Denial of Service (DoS) vulnerability exists in the CoreDNS DNS-over-QUIC…EPSS 1.2%7.5CVE-2023-30464Coredns.io coredns authentication bypass by spoofing vulnerabilityCoreDNS through 1.10.1 enables attackers to achieve DNS cache poisoning and inject fake responses via a birthday attack.EPSS 0.41%

Source: NIST National Vulnerability Database (record CVE-2026-33190), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.