CVE-2026-54526
CriticalCVSS 9.9Exploitation Probability (EPSS)
Low risk16th percentile - higher than 16% of all known CVEs
Summary
A vulnerability in Argo Workflows before versions 3.7.15 and 4.0.6 allows bypassing the allow-list fix for CVE-2026-31892. Through the ArtifactGC field in WorkflowSpec, a user can inject an arbitrary strategic merge patch into the artifact-GC pod, including dangerous settings like hostPath, privileged mode, or hostNetwork.
Risk Assessment
An attacker can gain unauthorized access to Kubernetes nodes, escalate privileges, or execute malicious code within the cluster context, compromising isolation and security.
Recommendation
Upgrade Argo Workflows to version 3.7.15 or 4.0.6 immediately. If upgrade is not possible, restrict access to ArtifactGC functionality and enforce strict security policies.
Original NVD description (English source)
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.