matrix-js-sdk has insufficient MXC URI validation which allows client-side path traversal

matrix-js-sdk is a Matrix messaging protocol Client-Server SDK for JavaScript. matrix-js-sdk before 34.11.0 is vulnerable to client-side path traversal via crafted MXC URIs. A malicious room member can trigger clients based on the matrix-js-sdk to issue arbitrary authenticated GET requests to the client's homeserver. Fixed in matrix-js-sdk 34.11.1.