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Fencer Vulns
high 7.7

CVE-2026-40886 json

Argo Workflows: Unchecked annotation parsing in pod informer crashes Argo Workflows controller

published 2026-04-23 6 mo ago modified 2026-10-26 13 d ago also BIT-argo-workflows-2026-40886 , EUVD-2026-25267 , GHSA-5jv8-h7qh-rf5p , GO-2026-5148

cvss
7.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/argoproj/argo-workflows/v4 4.0.5
  • go github.com/argoproj/argo-workflows/v3 3.7.14
  • bitnami argo-workflows 3.7.14, 4.0.5
  • argo_workflows_project argo_workflows 3.7.14, 4.0.5
  • argoproj argo_workflows 3.7.14, 4.0.5
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40886 updated cvss 7.7

github.com/argoproj/argo-workflows: Argo Workflows: Denial of Service via malformed workflow pod annotation

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-ml-pipelines-driver-rhel8, rhoai/odh-ml-pipelines-driver-rhel9, rhoai/odh-ml-pipelines-launcher-rhel8, rhoai/odh-ml-pipelines-launcher-rhel9, rhoai/odh-ml-pipelines-api-server-v2-rhel8, rhoai/odh-ml-pipelines-api-server-v2-rhel9, +8 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/argoproj/argo-workflows/security/advisories/GHSA-5jv8-h7qh-rf5p referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
CISA ADP 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
GitHub 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
OSV 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/argoproj/argo-workflows/v4
>=4.0.0, <4.0.5
4.0.5
go github.com/argoproj/argo-workflows/v3
>=3.7.0, <3.7.14
>=3.6.5, <=3.6.19
>=3.6.5
3.7.14
bitnami argo-workflows
>=3.6.5, <3.7.14
>=4.0.0, <4.0.5
3.7.14
4.0.5
go github.com/argoproj/argo-workflows
all versions
 no fix listed
go github.com/argoproj/argo-workflows/v2
all versions
 no fix listed

Affected products

  • argoproj argo-workflows
  • Red Hat Red Hat OpenShift AI (RHOAI)

Classification

Weakness
  • CWE-129 Improper Validation of Array Index
  • CWE-1285 Improper Validation of Specified Index, Position, or Offset in Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.