{"items":[{"id":"NVI-00013142","kind":"vulnerability","title":"fastify vulnerable to request body replacement via an async validation result collision","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-667r-xxjv-c9mm","CVE-2026-84504"],"plain_summary":"GitHub lists this reviewed advisory for fastify. 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-7236b227676b7f998870bf0658eef56c"],"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":"2026-09-30T23:45:46.000Z","value":"8.1 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-7236b227676b7f998870bf0658eef56c"}],"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-7236b227676b7f998870bf0658eef56c","url":"https://github.com/advisories/GHSA-667r-xxjv-c9mm","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-667r-xxjv-c9mm","publisher":"GitHub Advisory Database","observed_at":"2026-11-01T07:22:52.960Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-7236b227676b7f998870bf0658eef56c"],"technology":"fastify","known_exclusions":[],"conditions_summary":"### Impact\n\nFastify runs a route's validator and, for a result shaped like `{ value, error }`, unwraps it: an `error` becomes a validation failure and `value` replaces the request part. This convention is intended for synchronous custom compilers (for example Joi). A JSON Schema `$async` validator, however, resolves with the validated data itself, so Fastify applied the same unwrapping to it. If a request part validated by an `$async` schema contains a `value` property, Fastify replaced the whole request part with that nested value before the handler ran, so a `value` or `error` property in the payload was attacker-controlled. An application that dispatches operations from the validated request body could then act on data that never satisfied the route schema, leading to unauthorized state changes or disclosure. Reaching the vulnerable path requires the route to use an `$async` request schema.\n\n### Patches\n\nFastify no longer treats an asynchronous validation result as a `{ value, error }` wrapper: an async validator's resolved value is used only to determine pass or fail, and it can no longer replace the request part or inject an error. The synchronous custom-compiler contract is u","public_affected_ranges":["< 5.12.2"]}],"null_published_at":"2026-11-01T07:29:12.925Z","source_updated_at":"2026-09-30T23:45:46.000Z","source_disclosed_at":"2026-09-30T23:45:45.000Z","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":"2026-11-01T07:22:52.960Z"}],"next_cursor":null,"snapshot_revision":"42594"}