Improper Validation of Array Index in Argo Workflows - CVE-2026-40886
Published: April 23, 2026
Vulnerability identifier: #VU126908
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-40886
CWE-ID: CWE-129
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Argo
Affected software:
Argo Workflows
Argo Workflows
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper validation of array index in the pod informer's podGCFromPod() function when processing a workflow pod with a malformed workflows.argoproj.io/pod-gc-strategy annotation. A remote user can submit a workflow containing a crafted annotation to cause a denial of service.
The panic occurs in an informer goroutine outside the controller's recover scope, and the poisoned pod persists across restarts, causing a crash loop that halts workflow processing until the offending workflow is removed.
How to mitigate CVE-2026-40886
Install security update from vendor's website.