@fastify/multipart vulnerabilities

@fastify/multipart versions 5.3.0 through 10.1.6 does not propagate a parser error to the file stream when a request body ends inside a file part with no closing boundary, even though Content-Length is complete, the client does not abort, and no file size limit is exceeded. The plugin destroys the in-progress file stream without an error, so a handler doing asynchronous work before consuming the file attaches to a stream that never emits an error or end event, and the request never responds.

In @fastify/multipart, a multipart form-data parser for Fastify, versions from 3.0.0 up to but not including 10.1.1, request.saveRequestFiles() can leave completed temporary files on disk when a client disconnects during processing. An unauthenticated client can repeat this to cause persistent disk consumption and denial of service. The issue is fixed in version 10.1.1.

In @fastify/multipart, versions from 5.3.0 up to but not including 10.1.1, when the busboy fileSize limit truncates a file part, the plugin clears its internal current-file reference while the underlying stream is still open. If the client aborts the connection before sending the terminating boundary, saveRequestFiles() never settles, and the temporary file is never cleaned up. An unauthenticated client can repeat this to permanently leak temporary files and suspended handler executions, leading to disk and event-loop exhaustion. The issue is fixed in version 10.1.1.