CVE-2026-40886: Argoproj Argo Workflows

High severity, CVSS 7.7. EPSS: 0.6% chance of exploitation in the next 30 days.

Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. From 3.6.5 to 4.0.4, an unchecked array index in the pod informer's podGCFromPod() function causes a controller-wide panic when a workflow pod carries a malformed workflows.argoproj.io/pod-gc-strategy annotation. Because the panic occurs inside an informer goroutine (outside the controller's recover() scope), it crashes the entire controller process. The poisoned pod persists across restarts, causing a crash loop that halts all workflow processing until the pod is manually deleted. This vulnerability is fixed in 4.0.5 and 3.7.14.

Affected products

• Argoproj Argo Workflows: from 3.6.5, up to and including 3.6.19; from 3.7.0, before 3.7.14 (fixed in 3.7.14); from 4.0.0, before 4.0.5 (fixed in 4.0.5)

Published 2026-04-23. Last modified 2026-07-15.