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CVE Record

CVE-2026-42294: Argo Workflows: Unauthenticated Memory Exhaustion (DoS) in Webhook Interceptor

Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to versions 3.7.14 and 4.0.5, the Webhook Interceptor loads the entire request body into memory before authenticating the request or verifying its signature. This occurs on the /api/v1/events/ endpoint, which is publicly accessible (albeit intended for webhooks). An attacker can send a request with an extremely large body (e.g., multiple gigabytes), causing the Argo Server to allocate excessive memory, potentially leading to an Out-Of-Memory (OOM) crash and denial of service. This issue has been patched in versions 3.7.14 and 4.0.5.

HighCVSS 8.2Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Argo Workflows had a denial-of-service flaw in its webhook event endpoint. Before checking whether a request was legitimate, Argo Server could load the full body into memory. A very large unauthenticated request could exhaust memory and crash the service.

Executive priority

Treat as high priority where Argo Workflows supports production automation. A crash can interrupt Kubernetes workflow orchestration, but sources do not indicate data compromise or active exploitation.

Technical view

Prior to 3.7.14 and 4.0.5, the Webhook Interceptor on /api/v1/events/ read the entire request body before authentication or signature verification. The issue is CWE-770 with CVSS 4.0 score 8.2, affecting availability only.

Likely exposure

Exposure is likely for organizations running Argo Workflows below 3.7.14, or 4.0.0 through 4.0.4, where Argo Server's webhook endpoint is reachable from untrusted networks.

Exploitation context

The source bundle does not show KEV listing or confirmed active exploitation. The risk is unauthenticated network denial of service against a publicly reachable webhook endpoint, not data theft or code execution based on available evidence.

Researcher notes

Focus validation on version range, Argo Server exposure, and whether webhook traffic reaches /api/v1/events/ unauthenticated. The public evidence names the fixed versions and availability impact; it does not support broader product impact claims.

Mitigation direction

  • Upgrade affected 3.x deployments to Argo Workflows 3.7.14 or later.
  • Upgrade affected 4.0 deployments to Argo Workflows 4.0.5 or later.
  • Prioritize any Argo Server with /api/v1/events/ reachable from the internet.
  • If upgrade is delayed, check Argo project guidance for supported compensating controls.

Validation and detection

  • Inventory all Argo Workflows deployments and record exact server versions.
  • Confirm no deployment runs versions below 3.7.14 or 4.0.5.
  • Review ingress, gateway, and load balancer exposure for /api/v1/events/.
  • Check Argo Server logs and Kubernetes events for OOM kills or unexplained restarts.
Prepared
Confidence
high
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-770: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-42294 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.2 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
8Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.2CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——GitHub_M
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

8.2High
CVSS 4.0 vector shape for CVE-2026-42294Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPArgo Workflows: github.com/argoproj/argo-workflows: Argo Workflows: Denial of Service via large request body to Webhook Interceptor
other:Red Hat severity ratingcvssV3_1
  • 2026-05-09T05:01:16.989Z: Reported to Red Hat.
  • 2026-05-09T03:45:48.180Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
argoprojargo-workflows< 3.7.14, >= 4.0.0, < 4.0.5Listed
Weakness

CWE details

CWE-770

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-770 · source CWE mapping

Allocation of Resources Without Limits or Throttling

Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs