Orthanc server prior to version 1.5.8 does not enable basic authentication by default when remote access is enabled. This could result in unauthorized access by an attacker.

Orthanc versions before 1.12.2 are affected by a reflected cross-site scripting (XSS) vulnerability. The vulnerability was present in the server's error reporting.

Orthanc before 1.12.0 allows authenticated users with access to the Orthanc API to overwrite arbitrary files on the file system, and in specific deployment scenarios allows the attacker to overwrite the configuration, which can be exploited to trigger Remote Code Execution (RCE).