{"items":[{"id":"NVI-00018327","kind":"vulnerability","title":"parse-nested-form-data has Prototype Pollution via `__proto__` in FormData field names","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-xp7r-j8r6-j9h3","CVE-2026-45302"],"plain_summary":"GitHub lists this reviewed advisory for parse-nested-form-data. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-1182d6dc45ac9c71c8e2c0c189c90d9c"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-06-09T10:50:57.000Z","value":"8.2 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-1182d6dc45ac9c71c8e2c0c189c90d9c"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-1182d6dc45ac9c71c8e2c0c189c90d9c","url":"https://github.com/advisories/GHSA-xp7r-j8r6-j9h3","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-xp7r-j8r6-j9h3","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T20:56:39.448Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-1182d6dc45ac9c71c8e2c0c189c90d9c"],"technology":"parse-nested-form-data","known_exclusions":[],"conditions_summary":"## Summary\n\n`parseFormData()` walks bracket and dot-notation FormData field names into nested objects without filtering reserved property keys. A single FormData field whose name begins with `__proto__`, or contains `.__proto__.` mid-path, causes the parser to traverse onto `Object.prototype` and assign properties there, polluting the prototype chain of every plain object in the running process.\n\n## Details\n\nThe vulnerability is in `handlePathPart` in `src/index.ts`, which performs `currentObject[pathPart.path]` and `currentObject[pathPart.path] = val` for object-type path segments without rejecting reserved keys. When the segment is `__proto__`, the read returns `Object.prototype`, which then becomes the next traversal target, and the next assignment lands on the prototype.\n\nReproduction on a fresh install of `parse-nested-form-data@1.0.0`:\n\n```js\nimport { parseFormData } from 'parse-nested-form-data';\nconst fd = new FormData();\nfd.append('__proto__.polluted', 'yes');\nparseFormData(fd);\nconsole.log(({}).polluted); // -> 'yes'\nconsole.log(([]).polluted); // -> 'yes'\n```\n\nEquivalent vectors:\n\n- `__proto__[polluted]=yes`\n- `a.__proto__.polluted=yes` (mid-path traversal)\n- `a[0].__pro","public_affected_ranges":["<= 1.0.0"]}],"null_published_at":"2026-11-07T07:07:39.813Z","source_updated_at":"2026-06-09T10:50:57.000Z","source_disclosed_at":"2026-05-18T16:43:12.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-06T20:56:39.448Z"}],"next_cursor":null,"snapshot_revision":"42594"}