Incorrect Implementation of Authentication Algorithm Affecting kubernetes-dns-node-cache package, versions <1.26.8-r3


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.08% (24th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-KUBERNETESDNSNODECACHE-16423960
  • published6 May 2026
  • disclosed5 May 2026

Introduced: 5 May 2026

NewCVE-2026-33190  (opens in a new tab)
CWE-303  (opens in a new tab)

How to fix?

Upgrade Chainguard kubernetes-dns-node-cache to version 1.26.8-r3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kubernetes-dns-node-cache package and not the kubernetes-dns-node-cache package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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 Base Scores

version 3.1