CVE-2026-40886
Argo Workflows: Unchecked annotation parsing in pod informer crashes Argo Workflows controller
No known exploitation. EPSS puts it in the 46th percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.6% chance of exploitation activity in the next 30 days, which ranks it in the 46th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
6 events over 83 days, from the signal feeds we watch.
- Patch availablerecord updated
- Patch availablerecord updated
- Publishedweakness classified
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Scored 7.7 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity NoneNo integrity impact
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
Sources
References in the record
- github.com/argoproj/argo-workflows/security/advisories/GHSA-5jv8-h7qh-rf5p
- access.redhat.com/security/cve/CVE-2026-40886
- bugzilla.redhat.com/show_bug.cgi?id=2461236
And 1 more reference. See all after sign-in
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