CVE-2026-73231

Faker generates massive amounts of fake data in the browser and Node.js. Prior to 10.5.0, the faker.helpers.fake method in src/modules/helpers/eval.ts allows attacker-controlled fake templates to access the Function constructor through fakeEval.resolveProperty when a function returns another function, enabling arbitrary JavaScript code execution. This issue is fixed in version 10.5.0.

Faker generates massive amounts of fake data in the browser and Node.js. Prior to 10.5.0, the faker.helpers.fake method in src/modules/helpers/eval.ts allows attacker-controlled fake templates to access the Function constructor through fakeEval.resolveProperty when a function returns another function, enabling arbitrary JavaScript code execution. This issue is fixed in version 10.5.0.

Summary

faker.helpers.fake can be tricked into arbritary code execution.

Details

fakeEval.resolveProperty resolves properties on functions itself instead of resolving the nested function first. This can be addressed by recursively calling resolveProperty instead of accessing the property after one iteration.

PoC

Go to https://fakerjs.dev/ Open Browser console and run

await enableFaker(); // or import faker
faker.rawDefinitions.test = (() => () => {}); // Any function that returns a function
faker.helpers.fake(`{{test.constructor(alert('PowerLevel: Eval'))}}`);

Impact

The Fake method claims:

It is also NOT possible to use any non-faker methods or plain javascript in such patterns.

Which is objectively false, since any global gets fully accessible in the fake string.

Faker generates massive amounts of fake data in the browser and Node.js. Prior to 10.5.0, the faker.helpers.fake method in src/modules/helpers/eval.ts allows attacker-controlled fake templates to access the Function constructor through fakeEval.resolveProperty when a function returns another function, enabling arbitrary JavaScript code execution. This issue is fixed in version 10.5.0.

Faker generates massive amounts of fake data in the browser and Node.js. Prior to 10.5.0, the faker.helpers.fake method in src/modules/helpers/eval.ts allows attacker-controlled fake templates to access the Function constructor through fakeEval.resolveProperty when a function returns another function, enabling arbitrary JavaScript code execution. This issue is fixed in version 10.5.0.

Summary

faker.helpers.fake can be tricked into arbritary code execution.

Details

fakeEval.resolveProperty resolves properties on functions itself instead of resolving the nested function first. This can be addressed by recursively calling resolveProperty instead of accessing the property after one iteration.

PoC

Go to https://fakerjs.dev/ Open Browser console and run

await enableFaker(); // or import faker
faker.rawDefinitions.test = (() => () => {}); // Any function that returns a function
faker.helpers.fake(`{{test.constructor(alert('PowerLevel: Eval'))}}`);

Impact

The Fake method claims:

It is also NOT possible to use any non-faker methods or plain javascript in such patterns.

Which is objectively false, since any global gets fully accessible in the fake string.