Argo Workflows before versions 3.7.14 and 4.0.5 contains an incorrect authorization vulnerability (CWE-863) where users granted create Workflow permission can bypass the templateReferencing: Strict enforcement. This bypass permits escalation of privileges such as accessing the host network, switching service accounts, overriding pod security contexts, adding tolerations to schedule on control-plane nodes, and enabling service account token mounting. The vulnerability undermines the intended security controls of the Strict mode feature. The practical exploitation impact depends on additional Kubernetes cluster-level security controls like PodSecurity admission or OPA/Gatekeeper, which may block some actions. Clusters relying solely on Argo's Strict mode are fully exposed. The vulnerability has been fixed in Argo Workflows versions 3.7.14 and 4.0.5. No known exploits in the wild have been reported. The CVSS v3.1 score is 8.1 (High), reflecting network attack vector, low attack complexity, required privileges, no user interaction, and high confidentiality and integrity impact.

An attacker with create Workflow permission can bypass Argo Workflows' templateReferencing: Strict security feature, potentially gaining unauthorized host network access, switching service accounts, overriding pod security contexts, scheduling pods on control-plane nodes, and enabling service account token mounting. This can lead to significant confidentiality and integrity impacts within the Kubernetes cluster. The severity of the impact depends on additional Kubernetes-level security controls; clusters without such controls relying solely on Argo's Strict mode are fully exposed to these risks.

A fix for this vulnerability is available in Argo Workflows versions 3.7.14 and 4.0.5. Users should upgrade to these versions or later to remediate the issue. Additionally, Kubernetes clusters should enforce PodSecurity admission or use OPA/Gatekeeper policies to provide defense-in-depth. Since the vendor advisory does not specify alternative mitigations or indicate that no action is required, upgrading is the recommended remediation.