CVE-2026-40886
Because the panic occurs inside an informer goroutine (outside the controller's recover() scope), it crashes the entire controller process.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.7 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
- EPSS
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-129, CWE-1285
- Affected
- argoproj/argo workflows
- Source
- security-advisories@github.com
References
- https://github.com/argoproj/argo-workflows/security/advisories/GHSA-5jv8-h7qh-rf5pExploit, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-40886
- https://bugzilla.redhat.com/show_bug.cgi?id=2461236
- https://github.com/argoproj/argo-workflows/security/advisories/GHSA-5jv8-h7qh-rf5pExploit, Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40886.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.