CVE-2026-42183
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
Argo Workflows versions 4.0.0 to 4.0.5 have a nil pointer dereference in rbacAuthorization() in server/auth/gatekeeper.go, causing a panic (denial of service) for SSO users whose claims match a namespace-level RBAC rule but not an SSO-namespace rule when SSO_DELEGATE_RBAC_TO_NAMESPACE=true.
Risk Assessment
SSO users can inadvertently crash the Argo Workflows server, disrupting CI/CD pipelines.
Recommendation
Upgrade Argo Workflows to version 4.0.5 or later immediately.
Original NVD description (English source)
Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. From version 4.0.0 to before version 4.0.5, a nil pointer dereference in server/auth/gatekeeper.go rbacAuthorization() causes a panic (denial of service) for SSO users whose claims match a namespace-level RBAC rule but not an SSO-namespace rule, when SSO_DELEGATE_RBAC_TO_NAMESPACE=true. This issue has been patched in version 4.0.5.

