GHSA-c567-44rc-m5hq @rvf/set-get has a prototype pollution issue that's reachable via @rvf/core preprocessFormData (HTTP form data)

• npm @rvf/set-get: >= 7.0.0, < 7.0.2 → fixed in 7.0.2 • npm @rvf/set-get: >= 6.0.0, < 6.0.4 → fixed in 6.0.4

Summary `setPath` in `@rvf/set-get` (used by `@rvf/core` to flatten incoming form data into a nested object) does not block the keys `__proto__`, `constructor`, or `prototype` when walking a path. Because field names in submitted form data are passed directly to `setPath` via `preprocessFormData` (and through `parseFormData` / `validate`), an attacker who can submit a form to a Remix / React Router app using the library can set arbitrary properties on `Object.prototype` of the running server process. This is a default-reachable prototype pollution primitive: no special configuration is required. Any endpoint that accepts a form via `parseFormData` or runs a validator created with `createValidator` is affected. Affected versions • `@rvf/set-get` ` 'yes' ``` The field name `__proto__[polluted]` is the kind of value an attacker can submit from any HTML form or HTTP client. After the call, every plain object in the process inherits `polluted = 'yes'`. A second working payload is `constructor.prototype.=`, which goes through `setPath` walking `constructor` then `prototype`. Impact • Any property assignable on `Object.prototype` of the server process, set by a single unauthenticated HTTP request. • Persists for the life of the worker process and affects every subsequent request handled by the same process. • Direct downstream consequences depend on the host application and the rest of its dependency tree, but typical risks include: bypassing `if (obj.isAdmin)` style checks, injecting unintended config values into objects merged with user input, breaking template rendering, and crashing the worker by polluting properties used by other libraries (DoS). • Worth noting: the visible output of `preprocessFormData` does not contain the malicious key, so the attack leaves no obvious trace in request logs that show parsed bodies. CVSS `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L` (8.2, High) Integrity is High because the primitive lets the attacker change the meaning of property reads on every object in the process. Confidentiality is None and Availability is Low without a named downstream gadget; both could be higher in a specific consuming app. Remediation for users Upgrade to `@rvf/set-get` `7.0.2` or `6.0.4`. If you cannot upgrade `@rvf/core` directly, an `npm` / `pnpm` override on `@rvf/set-get` works. Credit Reported by Mohamed Bassia (@0xBassia).