Sunshine is a self-hosted game stream host for Moonlight. In versions prior to 2026.516.143833, the client-certificate authentication can be bypassed because of how OpenSSL verification results are handled. In src/crypto.cpp, the custom verify callback treats X509VERRUNABLETOGETISSUERCERTLOCALLY, X509VERRCERTNOTYETVALID, and X509VERRCERTHASEXPIRED as success. This can allow an untrusted certificate to pass authentication and access protected HTTPS endpoints. This issue has been fixed in version 2026.516.143833.

Sunshine for Windows, version v2025.122.141614, contains a DLL search-order hijacking vulnerability, allowing attackers to insert a malicious DLL in user-writeable PATH directories.

Sunshine is a self-hosted game stream host for Moonlight. Clients that experience a MITM attack during the pairing process may inadvertantly allow access to an unintended client rather than failing authentication due to a PIN validation error. The pairing attempt fails due to the incorrect PIN, but the certificate from the forged pairing attempt is incorrectly persisted prior to the completion of the pairing request. This allows access to the certificate belonging to the attacker.