{"id":"GHSA-c567-44rc-m5hq","revision":"a0f83adb7e894197bac5c989533a443d","records":[{"revision":"a0f83adb7e894197bac5c989533a443d","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-c567-44rc-m5hq","aliases":["CVE-2026-44483"],"title":"@rvf/set-get has a prototype pollution issue that's reachable via @rvf/core preprocessFormData (HTTP form data)","description":"## Summary\n\n`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.\n\nThis 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.\n\n## Affected versions\n\n- `@rvf/set-get` `< 7.0.2` (7.x line)\n- `@rvf/set-get` `< 6.0.4` (6.x line)\n\nReached through `@rvf/core` versions that depend on a vulnerable `@rvf/set-get` (current `8.1.0` resolves to `7.0.1` without the override).\n\n## Patched\n\n- `@rvf/set-get` `7.0.2`\n- `@rvf/set-get` `6.0.4`\n\nThe fix adds a `REJECT_KEYS` blocklist (`__proto__`, `constructor`, `prototype`) and throws when one is encountered while walking a path inside `setPath`.\n\n## Proof of concept\n\nInstall a vulnerable resolution and run on Node 18+:\n\n```json\n{\n  \"dependencies\": { \"@rvf/core\": \"8.1.0\" },\n  \"overrides\": { \"@rvf/set-get\": \"7.0.1\" }\n}\n```\n\n```js\nconst { preprocessFormData } = require('@rvf/core');\n\nconst form = new FormData();\nform.append(\"username\", \"alice\");\nform.append(\"__proto__[polluted]\", \"yes\");\n\npreprocessFormData(form);\nconsole.log(({}).polluted); // -> 'yes'\n```\n\nThe 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'`.\n\nA second working payload is `constructor.prototype.<key>=<value>`, which goes through `setPath` walking `constructor` then `prototype`.\n\n## Impact\n\n- Any property assignable on `Object.prototype` of the server process, set by a single unauthenticated HTTP request.\n- Persists for the life of the worker process and affects every subsequent request handled by the same process.\n- 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).\n- 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.\n\n## CVSS\n\n`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L` (8.2, High)\n\nIntegrity 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.\n\n## Remediation for users\n\nUpgrade 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.\n\n## Credit\n\nReported by Mohamed Bassia (@0xBassia).","state":0,"publishedAt":"2026-05-11T16:09:40+00:00","modifiedAt":"2026-09-10T03:50:46.5007165+00:00","affected":[{"ecosystem":"npm","name":"@rvf/set-get","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"7.0.0"},{"kind":"fixed","version":"7.0.2"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"@rvf/set-get","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"6.0.0"},{"kind":"fixed","version":"6.0.4"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/airjp73/rvf/security/advisories/GHSA-c567-44rc-m5hq","https://nvd.nist.gov/vuln/detail/CVE-2026-44483","https://github.com/airjp73/rvf"],"sourceUrl":"https://github.com/advisories/GHSA-c567-44rc-m5hq","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-c567-44rc-m5hq","identifiers":["GHSA-c567-44rc-m5hq","CVE-2026-44483"]},"retained":false,"historicalAffected":[]}],"coverage":[]}