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

> Attackers can cause a denial of service in Argo Workflows via a nil pointer dereference when SSO RBAC delegation is enabled.

- **Severity:** Low 2.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 May 2026
- **Updated:** 13 May 2026
- **Also known as:** BIT-argo-workflows-2026-42183, GHSA-p4gq-3vxj-f4jq, GO-2026-5527, MINI-2v63-q3mp-7wj3, MINI-756f-4w4r-26f5, MINI-7pqv-pqjw-2h85, MINI-993j-qwqp-6542, MINI-f2pv-fgvx-pj4p, MINI-g5j5-7pff-r7c2, MINI-hfq5-76p6-mmgq, MINI-hwqc-276m-c453, MINI-j5mx-frrx-mgx8, MINI-p2x7-fc65-88rr, MINI-qgwc-3hvq-m924, MINI-v75m-wvgw-7jv8

## What is CVE-2026-42183?

CVE-2026-42183 is a low-severity vulnerability in argoproj argo-workflows, published on 9 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-42183?

7 open source packages ship an affected version, including github.com/argoproj/argo-workflows/v4, argo-workflows and github.com/argoproj/argo-workflows. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/argoproj/argo-workflows/v4` | Go | From 4.0.0 | 4.0.5 |
| `github.com/argoproj/argo-workflows/v4` | Go | From 4.0.0 | 4.0.5 |
| `github.com/argoproj/argo-workflows/v4` | Go | From 4.0.0 | 4.0.5 |
| `argo-workflows` | Bitnami | From 4.0.0 | 4.0.5 |
| `github.com/argoproj/argo-workflows` | Go | All versions | None |
| `github.com/argoproj/argo-workflows/v2` | Go | All versions | None |
| `github.com/argoproj/argo-workflows/v3` | Go | All versions | None |

Products: Argoproj Argo Workflows.

## How do I fix CVE-2026-42183?

Upgrade github.com/argoproj/argo-workflows/v4 to 4.0.5 or later.

## Is CVE-2026-42183 being exploited?

There is no known exploitation of CVE-2026-42183 in the wild and no public exploit code.

## Other vulnerabilities in argoproj argo-workflows

- [CVE-2026-28229](https://insights.sbomify.com/CVE-2026-28229/): Argo Workflows has unauthorized access to Argo Workflows Template (critical 9.8)
- [CVE-2026-54526](https://insights.sbomify.com/CVE-2026-54526/): Argo Workflows: Incomplete fix for CVE-2026-31892: ArtifactGC.PodSpecPatch bypass of Strict/Secure templateReferencing (high 8.9)
- [CVE-2026-31892](https://insights.sbomify.com/CVE-2026-31892/): WorkflowTemplate Security Bypass via podSpecPatch in Strict/Secure Reference Mode (high 8.9)
- [CVE-2026-42295](https://insights.sbomify.com/CVE-2026-42295/): Argo Workflows: Exposure of artifact repository credentials (high 8.5)
- [CVE-2026-42297](https://insights.sbomify.com/CVE-2026-42297/): Argo Workflows Is Missing Authorization in Sync ConfigMap Provider (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42183 and fix it if it is affected.

What it is: CVE-2026-42183 is a low-severity vulnerability in argoproj argo-workflows, published on 9 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-42183 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/argoproj/argo-workflows/v4 (Go): affected from 4.0.0; fixed in 4.0.5
- github.com/argoproj/argo-workflows/v4 (Go): affected from 4.0.0; fixed in 4.0.5
- github.com/argoproj/argo-workflows/v4 (Go): affected from 4.0.0; fixed in 4.0.5
- argo-workflows (Bitnami): affected from 4.0.0; fixed in 4.0.5
- github.com/argoproj/argo-workflows (Go): affected all versions; no fix listed
- github.com/argoproj/argo-workflows/v2 (Go): affected all versions; no fix listed
- github.com/argoproj/argo-workflows/v3 (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42183/ (Markdown: https://insights.sbomify.com/CVE-2026-42183/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42183
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42183
- OSV: https://osv.dev/vulnerability/CVE-2026-42183

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42183/
Summaries are generated and may contain mistakes; the official description above is the record.