Model::update() is dangerous

The current Model::update() is very dangerous.

I created a sample vulnerable app.
https://github.com/kenjis/ci4-model-update-danger

PHP Code:

    public function update()
    {
        $id = $this->request->getPost('id');

        if ($this->request->getMethod() === 'post' && $this->validate([
            'title' => 'required|min_length[3]|max_length[255]',
            'body'  => 'required',
        ])) {
            $title = $this->request->getPost('title');
            $slug  = url_title($title, '-', true);

            $data = [
                'title' => $title,
                'slug'  => $slug,
                'body'  => $this->request->getPost('body'),
            ];
            $this->model->update($id, $data);

            return $this->response->redirect(site_url('news/' . $slug));
        }

        return $this->edit($id);
    } 


The above code has vulnerability. Do you know what's wrong?

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