CriticalCVE-2026-54526

    Argoproj Argo-workflows: Improper Access Control (CVE-2026-54526)

    Published Last modified Sources: CVE.org, OSV, Hersteller

    What is affected, what to do

    Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to 3.7.15 and 4.0.6, the allow-list fix for CVE-2026-31892 is incomplete because workflow/util/merge.go ValidateUserOverrides and SanitizeUserWorkflowSpec walk only the top-level fields of WorkflowSpec via reflection, and WorkflowSpec.ArtifactGC is allow-listed wholesale; the struct behind that field, WorkflowLevelArtifactGC, has a PodSpecPatch sub-field whose contents flow unmodified into util.ApplyPodSpecPatch on the artifact-GC pod, the same sink the original fix closed for WorkflowSpec.PodSpecPatch, so a user submitting a Workflow under templateReferencing: Strict or Secure (against a referenced WorkflowTemplate that declares an output artifact and setting spec.artifactGC.strategy: OnWorkflowCompletion) can still inject an arbitrary strategic merge patch into the artifact-GC pod, including hostPath volumes, privileged: true, arbitrary image and command, and hostNetwork: true, defeating the stated purpose of Strict/Secure reference mode.

    An exploit is publicly available. Update Argoproj Argo-workflows to version 3.7.15.

    Affected
    • Argoproj Argo-workflows gte 4.0.0, < 4.0.6..*
    • Argoproj Argo-workflows lt *..3.7.15
    Fixed in
    • Argoproj Argo-workflows 3.7.15

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.9

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    9.9

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: CVE.org, OSV, Hersteller

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 46.0

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    87.38 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    PoC (publicly reported)
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    9.9 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.9
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.9
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.5 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    46.0
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-284

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to 3.7.15 and 4.0.6, the allow-list fix for CVE-2026-31892 is incomplete because workflow/util/merge.go ValidateUserOverrides and SanitizeUserWorkflowSpec walk only the top-level fields of WorkflowSpec via reflection, and WorkflowSpec.ArtifactGC is allow-listed wholesale; the struct behind that field, WorkflowLevelArtifactGC, has a PodSpecPatch sub-field whose contents flow unmodified into util.ApplyPodSpecPatch on the artifact-GC pod, the same sink the original fix closed for WorkflowSpec.PodSpecPatch, so a user submitting a Workflow under templateReferencing: Strict or Secure (against a referenced WorkflowTemplate that declares an output artifact and setting spec.artifactGC.strategy: OnWorkflowCompletion) can still inject an arbitrary strategic merge patch into the artifact-GC pod, including hostPath volumes, privileged: true, arbitrary image and command, and hostNetwork: true, defeating the stated purpose of Strict/Secure reference mode. This issue is fixed in versions 3.7.15 and 4.0.6.

    Source: NVD (NIST), OSV (Open Source Vulnerabilities), GitHub Security Advisories, CVE.org (MITRE), cvelistv5

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    argoprojargo-workflows
    • < 3.7.15
    • ≥ 4.0.0, < 4.0.6
    • 3.7.15
    • —
    argoprojargo_workflows
    • < 3.7.15
    • 4.0.0 – < 4.0.6
    • 3.7.15
    • 4.0.6
    gogithub.com/argoproj/argo-workflows
    • —
    • —
    gogithub.com/argoproj/argo-workflows/v3
    • —
    • —
    gogithub.com/argoproj/argo-workflows/v4
    • 4.0.0
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-284Improper Access Control

      Pillar

      The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

      Entry at MITRE CWE-284

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    Reference tagged as exploitgithub.com (opens in a new tab)PoC (publicly reported)reported, not verified—

    References & sources

    • github.comargoproj/argo-workflows/commit/277e9cef0ad16d7eaaab253573d06959…web, x_refsource_MISC, Patch
    • github.comargoproj/argo-workflows/commit/358cc3968c8f06f1be0967e41df19108…web, x_refsource_MISC, Patch
    • github.comargoproj/argo-workflows/releases/tag/v3.7.15web, x_refsource_MISC, Product, Release notes
    • github.comargoproj/argo-workflows/releases/tag/v4.0.6web, x_refsource_MISC, Product, Release notes
    • github.comargoproj/argo-workflows/security/advisories/GHSA-48p8-g2fx-3wwmweb, x_refsource_CONFIRM, Exploit, Vendor advisory
    • NVD (NIST)vuln/detail/CVE-2026-54526web
    • github.comargoproj/argo-workflowspackage

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Initial analysis by NVDNVD

      Newly listed as affected:

      CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

      Show 8 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
      Product configurationadded
      —
      OR *cpe:2.3:a:argoproj:argo_workflows:*:*:*:*:*:go:*:* versions up to (excluding) 3.7.15 *cpe:2.3:a:argoproj:argo_workflows:*:*:*:*:*:go:*:* versions from (including) 4.0.0 up to (excluding) 4.0.6
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/argoproj/argo-workflows/commit/277e9cef0ad16d7eaaab253573d0695951a65dbd Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/argoproj/argo-workflows/commit/358cc3968c8f06f1be0967e41df191088db0b662 Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/argoproj/argo-workflows/releases/tag/v3.7.15 Types: Product, Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/argoproj/argo-workflows/releases/tag/v4.0.6 Types: Product, Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/argoproj/argo-workflows/security/advisories/GHSA-48p8-g2fx-3wwm Types: Exploit, Vendor Advisory
      Reference typeadded
      —
      CISA-ADP: https://github.com/argoproj/argo-workflows/security/advisories/GHSA-48p8-g2fx-3wwm Types: Exploit, Vendor Advisory

      Source identifier: nvd@nist.gov

    One NVD translation into another language is hidden.

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