Docker Sandboxes OAuth response masking could be bypassed with a case-variant token host

Docker Sandboxes compared OAuth token-endpoint hostnames case-sensitively when deciding whether to mask managed credential responses, while request routing treated DNS hostnames case-insensitively. Untrusted code inside a sandbox could use a case-variant hostname to reach the genuine provider endpoint while bypassing response masking. If a user completed the OAuth flow, the provider's access and refresh tokens could be returned unmasked to the sandbox, exposing host-managed credentials.