What’s Vulnerable › Vulnerabilities

CVE-2026-42183: Argo Workflows: SSO RBAC Delegation Nil Pointer Dereference DoS (gatekeeper.go)

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-09 · updated 2026-07-24
• Weakness: CWE-476

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.

Affected products

• argoproj argo-workflows: from 4.0.0 before 4.0.5 — fixed in 4.0.5

How to fix

Upgrade to a fixed version: argoproj argo-workflows 4.0.5. Check the vendor advisory for mitigations.

References

• https://github.com/argoproj/argo-workflows/commit/c4cc17d0c034fa9a9cc01ef1af6c8016c93071d4
• https://github.com/argoproj/argo-workflows/releases/tag/v4.0.5
• https://github.com/argoproj/argo-workflows/security/advisories/GHSA-p4gq-3vxj-f4jq

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