CVE-2026-40886 HIGH

CVE-2026-40886: Argo Workflows: Unchecked annotation parsing in pod informer crashes Argo Workflows controller

Vendor Argoproj
Product argo-workflows
Weakness CWE-129
Published April 23, 2026
Last update June 30, 2026

CVSS base score

7.7/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 23, 2026 CVE published
June 30, 2026 Record updated