Critical [CVE-2026-16242] Konnectivity proxy-server accepts agent connections without validating client certificates
This critical-severity Red Hat Linux advisory covers CVE-2026-16242 affecting multicluster engine for Kubernetes 2.11, multicluster engine for Kubernetes 2.17, multicluster engine for Kubernetes 2.6.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
Summary
A flaw was found in the Konnectivity proxy-server configuration for hosted control planes. The agent-facing listener was started without --cluster-ca-cert (and without token-based agent authentication), so client certificates were not validated.
A remote attacker who can reach the Konnectivity cluster endpoint could connect as an unauthenticated agent, join the routing pool, and potentially proxy, inspect, modify, or drop control-plane-to-node traffic. Because that endpoint is exposed so worker agents can connect, a successful attack can enroll an untrusted agent in the routing pool.
When the proxy selects that stream for a control-plane dial, the attacker may proxy, inspect, modify, or drop control-plane-to-node traffic, affecting confidentiality, integrity, and availability of that path. Red Hat severity: Critical — CVSS 9.4 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L).
Weakness: CWE-306.
Affected products named by the advisory: multicluster engine for Kubernetes 2.11; multicluster engine for Kubernetes 2.17; multicluster engine for Kubernetes 2.6; multicluster engine for Kubernetes 2.8; and 10 more.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
- multicluster-engine/hypershift-rhel9-operator:1784905766
- multicluster-engine/hypershift-rhel9-operator:1784945966
- multicluster-engine/hypershift-rhel9-operator:1784856942
- multicluster-engine/hypershift-rhel9-operator:1784905804
- multicluster-engine/hypershift-rhel9-operator:1784905783
- multicluster-engine/hypershift-rhel9-operator:1784905769
- openshift4/ose-hypershift-rhel8:1787001690
- openshift4/ose-hypershift-rhel9:1787055132
- openshift4/ose-hypershift-rhel9:1785534428
- openshift4/ose-hypershift-rhel9:1784914869
- openshift4/ose-hypershift-rhel9:1784912882
- openshift4/ose-hypershift-rhel9:1784913720
- openshift4/ose-hypershift-rhel9:1785288843
- openshift4/ose-hypershift-rhel9:1785301941
- openshift4/ose-hypershift-rhel9:1785192936
- RHSA-2026:46885
- RHSA-2026:47388
- RHSA-2026:47974
- RHSA-2026:48284
- RHSA-2026:47949
- RHSA-2026:47735
- RHSA-2026:47953
- RHSA-2026:56789
- RHSA-2026:56912
- RHSA-2026:50758
- RHSA-2026:47728
- RHSA-2026:48699
- RHSA-2026:48657
- RHSA-2026:48676
- RHSA-2026:48670
- RHSA-2026:48693
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
Mitigation checklist
- Until an update that configures Konnectivity agent authentication is applied, restrict network access to the Konnectivity cluster (agent) endpoint so that only trusted worker networks can reach it. For NodePort or LoadBalancer publishing, limit ingress to port 8091 to worker node subnet ranges. For Route-based publishing, restrict access to the Konnectivity route to trusted networks where possible. These controls reduce the chance that an unauthenticated attacker can reach the agent listener; they do not replace proper agent client-certificate (or token) authentication.
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.