Four security researchers have identified five cryptographic vulnerabilities in code libraries that can be exploited to undermine Matrix encrypted chat clients. This includes impersonating users and sending messages as them.
Our attacks break confidentiality and authentication against malicious homeservers. The underlying vulnerabilities show a lack of a unified and formal approach to security guarantees in Matrix.
(Habe leider keine gute deutsche Quelle gefunden.)
Das wirft schon ein ganz schlechtes Licht auf Matrix. Bin mir nicht so recht sicher, ob ich das weiterhin benutzen wollen würde.