A cross-site scripting error in Nextcloud Desktop client 2.6.4 allowed to present any html (including local links) when responding with invalid data on the login attempt.
Missing sanitization of a server response in Nextcloud Desktop Client 2.6.4 for Linux allowed a malicious Nextcloud Server to store files outside of the dedicated sync directory.
A memory corruption vulnerability exists in NextCloud Desktop Client v2.6.4 where missing ASLR and DEP protections in for windows allowed to corrupt memory.
A code injection in Nextcloud Desktop Client 2.6.2 for macOS allowed to load arbitrary code when starting the client with DYLD_INSERT_LIBRARIES set in the environment.