VULNERABILITY INTELLIGENCE

CVE-2026-33190

CVSS score7.5 HIGH
EPSS probability0.37%
CISA KEVNot currently listed
Published2026-05-05
Last modified2026-07-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Weakness classification

  • security-advisories@github.com: CWE-303

Primary references