Which versions of Argo Workflows are affected by CVE-2026-42295?

Argo Workflows versions 4.0.0-4.0.4 inadvertently log cloud storage and Git credentials in plaintext to Kubernetes pod logs, allowing any user with pod log read access to extract active AWS S3 keys,…. A patch is available.

How to fix or mitigate CVE-2026-42295?

Within 24 hours: Identify all Argo Workflows deployments running v4.0.0-v4.0.4 using `kubectl get deployment -A | grep argo-workflows` and note current versions. Within 7 days: Upgrade to Argo Workflows v4.0.5 or later (GitHub commit bdd40908 or newer) across all affected namespaces; validate no pod logs contain credentials post-upgrade using log scraping tools. Within 30 days: Rotate all S3 access/secret keys, GCS service account keys, Azure storage credentials, and Git credentials that may have been exposed in logs; review Kubernetes RBAC policies to restrict pod log read access to workflow namespaces using least-privilege principles.

Argo Workflows CVE-2026-42295

Q: What is the CVSS score of CVE-2026-42295?

CVE-2026-42295 has a CVSS 4.0 base score of 8.5 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

HIGH

Insufficiently Protected Credentials (CWE-522)

2026-05-04 https://github.com/argoproj/argo-workflows

GHSA-7vf8-2cr6-54mf

Kubernetes Microsoft Information Disclosure Red Hat

8.5

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.5 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Red Hat

5.5 MEDIUM

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

May 09, 2026 - 04:28 vuln.today

v2 (cvss_changed)

Re-analysis Queued

May 09, 2026 - 04:22 vuln.today

cvss_changed

CVSS changed

May 09, 2026 - 04:22 NVD

8.5 (HIGH)

Source Code Evidence Fetched

May 04, 2026 - 21:02 vuln.today

Analysis Generated

May 04, 2026 - 21:02 vuln.today

DescriptionGitHub Advisory

Summary

The workflow executor logs all artifact repository credentials (S3 access keys, secret keys, GCS service account keys, Azure account keys, Git passwords, etc.) in plaintext on artifact operation. Any user with read access to workflow pod logs can extract these credentials.

Note: This is an incomplete fix of CVE-2025-62157

Details

The logging driver passes the entire ArtifactDriver struct to the structured logger, for example: https://github.com/argoproj/argo-workflows/blob/59f1089b9875723ddffd524513e6bd5cb37e5e31/workflow/artifacts/logging/driver.go#L24

Exposed credential fields:

S3 (workflow/artifacts/s3/s3.go): AccessKey, SecretKey, SessionToken, ServerSideCustomerKey
OSS (workflow/artifacts/oss/oss.go): AccessKey, SecretKey, SecurityToken
GCS (workflow/artifacts/gcs/gcs.go): ServiceAccountKey

PoC

Create template

yml

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  name: cred-leak-test
  namespace: argo
spec:
  entrypoint: main
  templates:
  - name: main
    container:
      image: alpine:3.13
      command: [sh, -c]
      args: ["echo 'hello' > /tmp/output.txt"]
    outputs:
      artifacts:
      - name: output
        path: /tmp/output.txt
        s3:
          endpoint: minio:9000
          insecure: true
          bucket: my-bucket
          key: test-output.txt
          accessKeySecret:
            name: my-minio-cred
            key: accesskey
          secretKeySecret:
            name: my-minio-cred
            key: secretkey

Then check the logs

kubectl -n argo logs "cred-leak-test" -c wait <img width="1248" height="322" alt="image" src="https://github.com/user-attachments/assets/a5cf6d66-7d67-408d-8583-27d11ecf1507" />

Impact

Any user with Kubernetes RBAC permissions to read pod logs in the workflow namespace can extract artifact repository credentials.

AnalysisAI

Argo Workflows executor logs artifact repository credentials in plaintext to pod logs during artifact operations, exposing S3 access/secret keys, GCS service account keys, Azure storage keys, and Git passwords. Users with Kubernetes RBAC permissions to read pod logs in the workflow namespace can extract these credentials directly from workflow execution logs. This vulnerability affects Argo Workflows v4.0.0 through v4.0.4 and represents an incomplete fix of CVE-2025-62157. Vendor-released patch (v4.0.5) is available with GitHub commit bdd40908 removing credential-bearing struct logging. No public exploit identified at time of analysis, though exploitation is trivial given the included working proof-of-concept YAML.

Technical ContextAI

The vulnerability exists in Argo Workflows' artifact logging driver (workflow/artifacts/logging/driver.go), a Kubernetes-native workflow orchestration engine written in Go. The logging infrastructure passes entire ArtifactDriver structs to structured loggers using log.WithField("driver", d.ArtifactDriver), which serializes all struct fields including sensitive credential material. Affected artifact drivers include S3 (AccessKey, SecretKey, SessionToken, ServerSideCustomerKey), Alibaba OSS (AccessKey, SecretKey, SecurityToken), and Google Cloud Storage (ServiceAccountKey). This falls under CWE-522 (Insufficiently Protected Credentials), where secrets are exposed through unintended channels. The fix removes credential-bearing struct logging and switches to generic informational messages, demonstrating that credentials were never functionally necessary in log output. The underlying issue is a common Go logging anti-pattern where developers log entire structs without implementing custom masking methods or using struct tags to exclude sensitive fields. Kubernetes RBAC model exacerbates this because pod log access is a common debugging permission that inadvertently grants credential access when logs contain secrets.

RemediationAI

Upgrade to Argo Workflows v4.0.5 or later, released at https://github.com/argoproj/argo-workflows/releases/tag/v4.0.5, which implements the complete fix via commit bdd40908580f727c590c8743836e338b04fe4a87. The patch removes credential-bearing struct logging from workflow/artifacts/logging/driver.go, replacing log.WithField calls containing ArtifactDriver structs with generic informational messages. After upgrading, rotate all artifact repository credentials that may have been exposed in logs, including S3 access keys, GCS service account keys, Azure storage account keys, and Git tokens referenced in workflow templates. Purge historical pod logs from aggregation systems (Splunk, ELK, CloudWatch, Loki) covering the exposure period to prevent retroactive credential harvesting. For environments unable to immediately upgrade, implement a compensating control by restricting Kubernetes RBAC pod log read permissions (verbs: get, list on resource: pods/log) to only essential service accounts and administrators. This mitigation reduces attack surface but does not eliminate credential exposure in logs - service accounts and cluster admins with log access can still extract credentials. Additionally, configure log rotation with short retention periods (24-48 hours) and disable centralized log shipping for the argo namespace until patching is complete. Note these workarounds significantly impact debugging capabilities and should only be temporary measures.