GHSA-2w86-xfrc-g85r

Suggest an improvement
Source
https://github.com/advisories/GHSA-2w86-xfrc-g85r
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-2w86-xfrc-g85r/GHSA-2w86-xfrc-g85r.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-2w86-xfrc-g85r
Aliases
Published
2026-09-03T18:26:12Z
Modified
2026-09-03T18:30:03Z
Severity
  • 9.3 (Critical) CVSS_V4 - 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 CVSS Calculator
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.

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"
}
References

Affected packages

npm / orval

Package

Name
orval
View open source insights on deps.dev
Purl
pkg:npm/orval

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
8.21.0

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-2w86-xfrc-g85r/GHSA-2w86-xfrc-g85r.json"