GitHub Advisoryadvisory · npm

GHSA-2w86-xfrc-g85r Orval: RCE via schema property name -> computed-property-key injection in the MSW mock generator

CRITICAL Published 2026-09-03 Modified 2026-09-03 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

Weakness · CWE (2)

  • CWE-89 Improper Neutralization of Special Elements used in an SQL Command weakness
  • CWE-95 Improper Neutralization of Directives in Dynamically Evaluated Code weakness

References