NULL pointer dereference in Argo Workflows - CVE-2026-42183
Published: April 23, 2026
Vulnerability identifier: #VU126906
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-42183
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a null pointer dereference in the rbacAuthorization() function in server/auth/gatekeeper.go when handling API requests from SSO users whose claims match a namespace-level RBAC rule but not an SSO-namespace rule. A remote user can send a request to an affected workflow namespace to cause a denial of service.
Exploitation requires SSO RBAC delegation to namespace to be enabled with SSO_DELEGATE_RBAC_TO_NAMESPACE=true.
Affected software
Argo Workflows
How to mitigate CVE-2026-42183
Install security update from vendor's website.
Argo Workflows - update to 4.0.5