GitHub Advisoryadvisory · npm
GHSA-2w86-xfrc-g85r Orval: RCE via schema property name -> computed-property-key injection in the MSW mock generator
CRITICAL
Official page ↗
- Aliases
- CVE-2026-71867
- Ecosystem
- npm
- Packages
- orval
- Severity
- Critical
- CVSS vector
- 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
- Weaknesses
- CWE-89, CWE-95
- Reviewed
- 2026-09-03
Affected packages
• npm orval: < 8.21.0 → fixed in 8.21.0
Description
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
```ts
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("","")]: 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.
Related
Alias · CVE (1)
- CVE-2026-71867 Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. vulnerability
References
- https://github.com/orval-labs/orval/security/advisories/GHSA-2w86-xfrc-g85r web
- https://nvd.nist.gov/vuln/detail/CVE-2026-71867 advisory
- https://github.com/orval-labs/orval/pull/3692 web
- https://github.com/orval-labs/orval/commit/8ef1bfdf3f9bcaf9dabfbe2e42887f1c0e159ab6 web
- https://github.com/orval-labs/orval package
- https://github.com/orval-labs/orval/releases/tag/v8.21.0 web