CVE-2026-42183
Argo Workflows: SSO RBAC Delegation Nil Pointer Dereference DoS (gatekeeper.go)
EPSS 0.05%
Description
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.
How to fix CVE-2026-42183
To remediate CVE-2026-42183, upgrade the affected package to a fixed version below.
- —upgrade to 4.0.5 or later
- —upgrade to 4.0.5 or later
Is CVE-2026-42183 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- >= 4.0.0, < 4.0.5
- >= 4.0.0, < 4.0.5
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |