CVE-2026-40886

Summary

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 Software

VendorProductVersion RangeStatus
argoprojargo-workflows>= 4.0.0, < 4.0.5affected
argoprojargo-workflows>= 3.7.0, < 3.7.14affected
argoprojargo-workflows>= 3.6.5, <= 3.6.19affected

Weaknesses

  • CWE-129: CWE-129: Improper Validation of Array Index

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

github.com/argoproj/argo-workflows: Argo Workflows: Denial of Service via malformed workflow pod annotation

Additional References

References