Medium severity · published May 9, 2026
CVE-2026-42183
Argo Workflows: SSO RBAC Delegation Nil Pointer Dereference DoS (gatekeeper.go)
6.5
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AR
argo-workflows · argoproj
>= 4.0.0, < 4.0.5 · source: vendor
AW
Argo Workflows · Argoproj
4.0.0 before 4.0.5 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42183
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42183
Patch
https://github.com/argoproj/argo-workflows/commit/c4cc17d0c034fa9a9cc01ef1af6c8016c93071d4
Release Notes
https://github.com/argoproj/argo-workflows/releases/tag/v4.0.5
Exploit
https://github.com/argoproj/argo-workflows/security/advisories/GHSA-p4gq-3vxj-f4jq
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