CloudSec Research Group

Independent vulnerability research and security advisories for cloud-native infrastructure.

● Independent research ● Coordinated disclosure
CVSS 8.1 — HIGH CSRG-2026-0428
Overview
Timeline
Impact
Mitigation
IOCs / Detection
CVE-2026-4881 — Kubernetes Kubelet Certificate Rotation Race Condition

Race condition in kubelet TLS certificate rotation affecting Kubernetes v1.28 through v1.31. During automatic certificate renewal, a ~90-second exploitation window allows MitM interception of kubelet API traffic on port 10250. The vulnerability permits unauthenticated API calls from within the cluster network, enabling arbitrary command execution in pods on affected nodes.

Published: Apr 28, 2026 Updated: May 15, 2026 ID: CSRG-2026-0428
Read advisory

Timeline

Apr 28, 2026 Advisory published
May 15, 2026 Advisory updated
May 15, 2026 Advisory indexed

At a Glance

TypeRace Condition
Componentkubelet (TLS certificate rotation)
Attack VectorNetwork (Adjacent)
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh