Vulnerability · Published Apr 23, 2026 · Assigned by GitHub_M
CVE-2026-40886Argo Workflows: Unchecked annotation parsing in pod informer crashes Argo Workflows controller
High 7.7
In plain English
A high-severity security flaw in argo-workflows from argoproj. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. From 3.6.5 to 4.0.4, an unchecked array index in the pod informer's podGCFromPod() function causes a controller-wide panic when a workflow pod carries a malformed workflows.argoproj.io/pod-gc-strategy annotation. Because the panic occurs inside an informer goroutine (outside the controller's recover() scope), it crashes the entire controller process. The poisoned pod persists across restarts, causing a crash loop that halts all workflow processing until the pod is manually deleted. This vulnerability is fixed in 4.0.5 and 3.7.14.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/argoproj/argo-workflows | no fix listed | GO-2026-5148 |
| Go | github.com/argoproj/argo-workflows/v2 | no fix listed | GO-2026-5148 |
| Go | github.com/argoproj/argo-workflows/v3 | 3.7.14 | GO-2026-5148 |
| Go | github.com/argoproj/argo-workflows/v3 | 3.7.14 | GHSA-5jv8-h7qh-rf5p |
| Go | github.com/argoproj/argo-workflows/v3 | no fix listed | GHSA-5jv8-h7qh-rf5p |
| Go | github.com/argoproj/argo-workflows/v3 | no fix listed | GO-2026-5148 |
| Go | github.com/argoproj/argo-workflows/v4 | 4.0.5 | GO-2026-5148 |
| Go | github.com/argoproj/argo-workflows/v4 | 4.0.5 | GHSA-5jv8-h7qh-rf5p |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| argoproj | argo-workflows | >= 4.0.0, < 4.0.5>= 3.7.0, < 3.7.14>= 3.6.5, <= 3.6.19 |
Weakness: CWE-129, CWE-1285 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
References
- https://github.com/argoproj/argo-workflows/security/advisories/GHSA-5jv8-h7qh-rf5p x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-40886 vdb-entry, x_refsource_REDHAT
- RHBZ#2461236 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40886.json x_sadp-csaf-vex