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FKIE_CVE-2026-49143

Vulnerability from fkie_nvd - Published: 2026-06-02 21:16 - Updated: 2026-07-22 19:10
Severity
8.8 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
BrowserStack Runner through 0.9.5 contains a remote code execution vulnerability in the /_log HTTP handler that allows unauthenticated network-adjacent attackers to execute arbitrary code by submitting crafted JSON request bodies to the handler, which passes user-supplied data to vm.runInNewContext() combined with eval(). Attackers can escape the Node.js vm sandbox by leveraging a host-context Function reference through util.format to access the host process via this.constructor.constructor, achieving full remote code execution on the underlying system without any authentication.
References
disclosure@vulncheck.comhttps://github.com/browserstack/browserstack-runner/security/advisories/GHSA-6vr3-7wcx-v5g5
disclosure@vulncheck.comhttps://www.vulncheck.com/advisories/browserstack-runner-unauthenticated-rce-via-log-http-handler
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/browserstack/browserstack-runner/security/advisories/GHSA-6vr3-7wcx-v5g5
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "affected",
          "packageURL": "pkg:github/browserstack/browserstack-runner",
          "product": "browserstack-runner",
          "repo": "https://github.com/browserstack/browserstack-runner",
          "vendor": "browserstack",
          "versions": [
            {
              "lessThanOrEqual": "0.9.5",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "cveTags": [
    {
      "sourceIdentifier": "disclosure@vulncheck.com",
      "tags": [
        "unsupported-when-assigned"
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "BrowserStack Runner through 0.9.5 contains a remote code execution vulnerability in the /_log HTTP handler that allows unauthenticated network-adjacent attackers to execute arbitrary code by submitting crafted JSON request bodies to the handler, which passes user-supplied data to vm.runInNewContext() combined with eval(). Attackers can escape the Node.js vm sandbox by leveraging a host-context Function reference through util.format to access the host process via this.constructor.constructor, achieving full remote code execution on the underlying system without any authentication."
    },
    {
      "lang": "es",
      "value": "BrowserStack Runner hasta la versi\u00f3n 0.9.5 contiene una vulnerabilidad de ejecuci\u00f3n remota de c\u00f3digo en el gestor HTTP /_log que permite a atacantes adyacentes a la red sin autenticaci\u00f3n ejecutar c\u00f3digo arbitrario al enviar cuerpos de solicitud JSON manipulados al gestor, el cual pasa datos proporcionados por el usuario a vm.runInNewContext() combinado con eval(). Los atacantes pueden escapar del sandbox vm de Node.js aprovechando una referencia de funci\u00f3n de contexto de host a trav\u00e9s de util.format para acceder al proceso del host a trav\u00e9s de this.constructor.constructor, logrando una ejecuci\u00f3n remota de c\u00f3digo completa en el sistema subyacente sin autenticaci\u00f3n alguna."
    }
  ],
  "id": "CVE-2026-49143",
  "lastModified": "2026-07-22T19:10:00.120",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "ADJACENT",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-49143",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-03T14:02:08.658694Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-02T21:16:28.070",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/browserstack/browserstack-runner/security/advisories/GHSA-6vr3-7wcx-v5g5"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://www.vulncheck.com/advisories/browserstack-runner-unauthenticated-rce-via-log-http-handler"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/browserstack/browserstack-runner/security/advisories/GHSA-6vr3-7wcx-v5g5"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Secondary"
    }
  ]
}



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