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GHSA-2W86-XFRC-G85R

Vulnerability from github – Published: 2026-09-03 18:26 – Updated: 2026-09-03 18:26
VLAI
Summary
Orval: RCE via schema property name -> computed-property-key injection in the MSW mock generator
Details

Summary

orval, when generating MSW mocks (output.mock: true), emits each schema property name as a single-quoted object key in the mock factory WITHOUT escaping the single quote. A ' in a property name closes the key and lands in object-literal context, where an injected computed property key [expr] is evaluated when the mock factory is called (e.g. in tests / MSW handlers) -> RCE. The property name is a pure data field. Verified on orval 8.19.0 / Node.

Details

export const getOpResponseMock = (...): Thing => ({'x': 0, [require("fs").writeFileSync("PWNED","")]: 0, 'y': faker...., ...overrideResponse});

Safe elsewhere: the zod schema double-quotes the property name; the TS interface key is a type (DoS only). Distinct from orval's $ref / route-path / server-url / zod-default findings.

PoC

reproduce.sh (+ make_spec.py) attached: a property name x': 0, [require("fs").writeFileSync("<marker>","")]: 0, 'y -> mock object literal; calling the mock factory writes the marker. Verified on 8.19.0.

Impact

JavaScript / OS command execution (via child_process) on the machine of anyone who generates orval mocks from an attacker controlled spec and runs them (tests / MSW).

Suggested fix

Escape the property name for the JS string key (JSON.stringify), and never interpolate a raw property name adjacent to [ ] in object-literal position.

Severity
9.3 (Critical)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "orval"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.21.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-71867"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-89",
      "CWE-95"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-03T18:26:12Z",
    "nvd_published_at": "2026-08-19T18:17:24Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\norval, when generating MSW mocks (output.mock: true), emits each schema property name as a single-quoted object key in the mock factory WITHOUT escaping the single quote. A \u0027 in a property name closes the key and lands in object-literal context, where an injected computed property key [expr] is evaluated when the mock factory is called (e.g. in tests / MSW handlers) -\u003e RCE. The property name is a pure data field. Verified on orval 8.19.0 / Node. \n\n### Details\n\n```ts\nexport const getOpResponseMock = (...): Thing =\u003e ({\u0027x\u0027: 0, [require(\"fs\").writeFileSync(\"PWNED\",\"\")]: 0, \u0027y\u0027: faker...., ...overrideResponse});\n```\n\nSafe elsewhere: the zod schema double-quotes the property name; the TS interface key is a type (DoS only). Distinct from orval\u0027s $ref / route-path / server-url / zod-default findings.\n\n### PoC\n\nreproduce.sh (+ make_spec.py) attached: a property name `x\u0027: 0, [require(\"fs\").writeFileSync(\"\u003cmarker\u003e\",\"\")]: 0, \u0027y` -\u003e mock object literal; calling the mock factory writes the marker. Verified on 8.19.0.\n\n### Impact\n\nJavaScript / OS command execution (via child_process) on the machine of anyone who generates orval mocks from an attacker controlled spec and runs them (tests / MSW).\n\n### Suggested fix\n\nEscape the property name for the JS string key (JSON.stringify), and never interpolate a raw property name adjacent to [ ] in object-literal position.",
  "id": "GHSA-2w86-xfrc-g85r",
  "modified": "2026-09-03T18:26:12Z",
  "published": "2026-09-03T18:26:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/orval-labs/orval/security/advisories/GHSA-2w86-xfrc-g85r"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-71867"
    },
    {
      "type": "WEB",
      "url": "https://github.com/orval-labs/orval/pull/3692"
    },
    {
      "type": "WEB",
      "url": "https://github.com/orval-labs/orval/commit/8ef1bfdf3f9bcaf9dabfbe2e42887f1c0e159ab6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/orval-labs/orval"
    },
    {
      "type": "WEB",
      "url": "https://github.com/orval-labs/orval/releases/tag/v8.21.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Orval: RCE via schema property name -\u003e computed-property-key injection in the MSW mock generator"
}



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