Argo Workflows: Incomplete fix for CVE-2026-31892: ArtifactGC.PodSpecPatch bypass of Strict/Secure templateReferencing

Summary

Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to 3.7.15 and 4.0.6, the allow-list fix for CVE-2026-31892 is incomplete because workflow/util/merge.go ValidateUserOverrides and SanitizeUserWorkflowSpec walk only the top-level fields of WorkflowSpec via reflection, and WorkflowSpec.ArtifactGC is allow-listed wholesale; the struct behind that field, WorkflowLevelArtifactGC, has a PodSpecPatch sub-field whose contents flow unmodified into util.ApplyPodSpecPatch on the artifact-GC pod, the same sink the original fix closed for WorkflowSpec.PodSpecPatch, so a user submitting a Workflow under templateReferencing: Strict or Secure (against a referenced WorkflowTemplate that declares an output artifact and setting spec.artifactGC.strategy: OnWorkflowCompletion) can still inject an arbitrary strategic merge patch into the artifact-GC pod, including hostPath volumes, privileged: true, arbitrary image and command, and hostNetwork: true, defeating the stated purpose of Strict/Secure reference mode. This issue is fixed in versions 3.7.15 and 4.0.6.

Timeline

1. Jul 16, 2026, 7:07 PM UTCCVE published
2. Jul 17, 2026, 1:57 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: total

3. Jul 17, 2026, 1:57 PM UTCRecord last updated

Affected versions

• argoproj argo-workflows

  fixed in 3.7.15; From 4.0.0 · fixed in 4.0.6

• github.com/argoproj/argo-workflows/v4Go

  From 4.0.0 · fixed in 4.0.6

• github.com/argoproj/argo-workflows/v3Go

  fixed in 3.7.15

• github.com/argoproj/argo-workflowsGo

  through 2.5.3-rc4

• github.com/argoproj/argo-workflowsGo

  All versions

• github.com/argoproj/argo-workflows/v2Go

  All versions

References 5