How severe is GHSA-p4gq-3vxj-f4jq?

No CVSS score has been assigned to GHSA-p4gq-3vxj-f4jq yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-p4gq-3vxj-f4jq?

GHSA-p4gq-3vxj-f4jq affects the following packages: github.com/argoproj/argo-workflows/v4 (Go). Ecosystems affected: Go.

How do I fix GHSA-p4gq-3vxj-f4jq?

Update github.com/argoproj/argo-workflows/v4 to 4.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p4gq-3vxj-f4jq is resolved across your whole dependency graph.

How do I detect GHSA-p4gq-3vxj-f4jq in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/argoproj/argo-workflows/v4. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-p4gq-3vxj-f4jq if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-p4gq-3vxj-f4jq?

O3 pinpoints whether GHSA-p4gq-3vxj-f4jq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-p4gq-3vxj-f4jq actively exploited in the wild?

No public exploit code has been indexed for GHSA-p4gq-3vxj-f4jq yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-p4gq-3vxj-f4jq?

GHSA-p4gq-3vxj-f4jq has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 30th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-p4gq-3vxj-f4jq published, and has it been updated?

GHSA-p4gq-3vxj-f4jq was published on May 4, 2026 and was last updated on July 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-p4gq-3vxj-f4jq

GHSA-p4gq-3vxj-f4jq is a security vulnerability in github.com/argoproj/argo-workflows/v4. O3 Security confirms whether GHSA-p4gq-3vxj-f4jq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Argo Affected by SSO RBAC Delegation Nil Pointer Dereference DoS (gatekeeper.go)

Also known asBIT-argo-workflows-2026-42183CVE-2026-42183GO-2026-5527

Published

May 4, 2026

Updated

Jul 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk30th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐹github.com/argoproj/argo-workflows/v4

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

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.

Details

When getServiceAccount(claims, ssoNamespace) returns nil (no matching rule), the error is suppressed and loginAccount remains nil. If RBAC delegation finds a matching namespaceAccount, line 304 calls precedence(loginAccount) which unconditionally accesses serviceAccount.Annotations — nil pointer dereference.

Affected code (v4.0.4):

// gatekeeper.go:304
} else if precedence(namespaceAccount) > precedence(loginAccount) {
    // loginAccount is nil here -> precedence(nil) -> PANIC

// gatekeeper.go:232-234
func precedence(serviceAccount *corev1.ServiceAccount) int {
    i, _ := strconv.Atoi(serviceAccount.Annotations[common.AnnotationKeyRBACRulePrecedence])
    return i
}

PoC

Live-tested 2026-04-17: kind cluster, Argo Workflows v4.0.4, Dex v2.43.1 OIDC provider.

Deploy Argo Workflows with --auth-mode=sso --auth-mode=client, SSO pointing to Dex, RBAC enabled.
Set SSO_DELEGATE_RBAC_TO_NAMESPACE=true on the argo-server deployment.
Create an RBAC ServiceAccount with workflows.argoproj.io/rbac-rule: "true" annotation in a target namespace (e.g., target-ns).
Do not create a matching RBAC rule in the SSO namespace (argo).
Authenticate via the Dex SSO flow.
Request GET /api/v1/workflows/target-ns with the SSO session cookie.
Server returns HTTP 500: {"code":13,"message":"runtime error: invalid memory address or nil pointer dereference"}
Server logs: Recovered from panic with stack trace at gatekeeper.go:233 (precedence()) called from gatekeeper.go:304.

Every subsequent API request from affected SSO users triggers the same panic.

Impact

Permanent denial of service for any SSO user whose claims don't match SSO-namespace RBAC but do match a target namespace rule. Realistic in multi-tenant deployments with per-namespace RBAC. The gRPC recovery interceptor catches the panic so the server process survives, but the affected user gets HTTP 500 on every request.

Suggested Fix

Add nil check: if loginAccount == nil || precedence(namespaceAccount) > precedence(loginAccount)

AI Disclosure

This advisory was prepared with AI assistance (Claude Code, Anthropic).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/argoproj/argo-workflows/v4`	≥ 4.0.0&&< 4.0.5	4.0.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/argoproj/argo-workflows/v4. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/argoproj/argo-workflows/v4 to 4.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p4gq-3vxj-f4jq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-p4gq-3vxj-f4jq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-p4gq-3vxj-f4jq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary 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`. ### Details When `getServiceAccount(claims, ssoNamespace)` returns nil (no matching rule), the error is suppressed and `loginAccount` remains nil. If RBAC delegation finds a matching `namespaceAccount`, line 304 calls `precedence(loginAccount)` which unconditionally accesses `serviceAccount.Annotations` — nil pointer dereference. **Af

O3 Security · Impact-Aware SCA

Is GHSA-p4gq-3vxj-f4jq in your dependencies?

O3 detects GHSA-p4gq-3vxj-f4jq across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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