How severe is CVE-2026-40886?

CVE-2026-40886 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-40886 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40886?

CVE-2026-40886 affects Argoproj Argo Workflows. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40886?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40886 have an EU (EUVD) identifier?

Yes. CVE-2026-40886 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25267.

When was CVE-2026-40886 published?

CVE-2026-40886 was published on 2026-04-23 and last updated on 2026-06-30.

CVE-2026-40886

CVE-2026-40886 is a high-severity vulnerability in Argoproj Argo Workflows with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-129.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-25267
Weakness: CWE-129
Affected product: Argoproj Argo Workflows
Published: 2026-04-23
Last modified: 2026-06-30

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.

Frequently asked questions

What is CVE-2026-40886?: 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.
How severe is CVE-2026-40886?: CVE-2026-40886 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-40886 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40886?: CVE-2026-40886 affects Argoproj Argo Workflows. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40886?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40886 have an EU (EUVD) identifier?: Yes. CVE-2026-40886 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25267.
When was CVE-2026-40886 published?: CVE-2026-40886 was published on 2026-04-23 and last updated on 2026-06-30.

References

Affected products (1)

cpe:2.3:a:argoproj:argo_workflows:*:*:*:*:*:go:*:*

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