CVE-2026-42294 Argo Workflows: Unauthenticated Memory Exhaustion (DoS) in Webhook Interceptor
Unauthenticated attackers can cause denial of service in Argo Workflows by sending large payloads to the webhook endpoint, exhausting server memory.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42294?
CVE-2026-42294 is a high-severity denial of service vulnerability in argoproj argo-workflows, published on 9 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to versions 3.7.14 and 4.0.5, the Webhook Interceptor loads the entire request body into memory before authenticating the request or verifying its signature. This occurs on the /api/v1/events/ endpoint, which is publicly accessible (albeit intended for webhooks). An attacker can send a request with an extremely large body (e.g., multiple gigabytes), causing the Argo Server to allocate excessive memory, potentially leading to an Out-Of-Memory (OOM) crash and denial of service. This issue has been patched in versions 3.7.14 and 4.0.5.
Weakness: CWE-770
Which versions are affected by CVE-2026-42294?
9 open source packages ship an affected version, including github.com/argoproj/argo-workflows/v3, argo-workflows and github.com/argoproj/argo-workflows. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/argoproj/argo-workflows/v3 Go | All versions | 3.7.14 |
github.com/argoproj/argo-workflows/v3 Go | All versions | 3.7.14 |
github.com/argoproj/argo-workflows/v3 Go | All versions | 3.7.14 |
argo-workflows Bitnami | All versions | 3.7.14, 4.0.5 |
github.com/argoproj/argo-workflows Go | All versions | None |
github.com/argoproj/argo-workflows/v2 Go | All versions | None |
3 more packages
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 |
Products include Argoproj Argo Workflows.
How do I fix CVE-2026-42294?
Upgrade github.com/argoproj/argo-workflows/v3 to 3.7.14 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-42294 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42294 exists.
Other vulnerabilities in argoproj argo-workflows
- CVE-2026-28229 Argo Workflows has unauthorized access to Argo Workflows Template
- CVE-2026-54526 Argo Workflows: Incomplete fix for CVE-2026-31892: ArtifactGC.PodSpecPatch bypass of Strict/Secure templateReferencing
- CVE-2026-31892 WorkflowTemplate Security Bypass via podSpecPatch in Strict/Secure Reference Mode
- CVE-2026-42295 Argo Workflows: Exposure of artifact repository credentials
- CVE-2026-42297 Argo Workflows Is Missing Authorization in Sync ConfigMap Provider
Sources
Also known as BIT-argo-workflows-2026-42294, ECHO-9dd3-fd4f-da54, GHSA-jcc8-g2q4-9fxq, GO-2026-5462, MINI-4fh2-cg3m-6q93, MINI-98fq-x88p-g833 and 7 more.