I am very new to Android app development and I started out with the idea of fixing a small defect in an app. However, I got sucked further in and found that a payment processing company that we use has introduced a new client library that contains a security vulnerability. Therefore, I don't want to use the library. Rather than switch processors I'm trying to find a workaround. Since we use the processor's Web-based payments page for the Web app, one possibility is to embed the same web page in the Android app.
I'm wondering whether using the Web page this way inside an Android WebView would create any new vulnerabilities that I should be aware of. I'm asking about Android specifically. If anyone else has done something similar and looked into the security implications, I'd like to hear from you.