GHSA-2W86-XFRC-G85R
Vulnerability from github – Published: 2026-09-03 18:26 – Updated: 2026-09-03 18:26Summary
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.
{
"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"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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