GHSA-j3f2-48v5-ccww

## Summary

protobufjs parsed option names by advancing through schema tokens until it reached an `=` token, without checking for end of input. A crafted `.proto` schema that opens an option declaration but ends prematurely could cause the option parser to loop without ever terminating.

This affects the reflection parsing path (`parse`, `Root.load`, `Root.loadSync`).

## Impact

An attacker who can provide or influence `.proto` schema text parsed by an application may be able to cause the parsing call to never return. Because Node.js is single-threaded, the blocked event loop prevents all other work in the process, resulting in a denial of service that persists until the process is externally terminated.

Applications that only encode or decode protobuf binary data with trusted schemas are not directly affected.

## Preconditions

- The application must parse `.proto` schema text influenced by an attacker. - The schema must be parsed through APIs such as `parse`, `Root.load`, or `Root.loadSync`. - The crafted input must begin an option declaration that ends before its `=` assignment.

## Workarounds

Do not parse `.proto` schemas from untrusted sources with affected versions. If untrusted schema text must be accepted, isolate parsing in a process or worker that can be safely terminated and bound it with a timeout, so a non-returning parse call cannot deny service to the rest of the application.