Looking into the attachment, I can see that there is an issue with CVEs mentioned in violations export file and this issue is with Debian. The underlying image that is used for functions basically has this issue.
There are many reasons for CVEs to still be shown in production images and you can read this for information: https://github.com/docker-library/faq#why-does-my-security-scanner-show-that-an-image-has-cves
If any CVEs that you think might affect you. You can track them using this link: https://security-tracker.debian.org/tracker/
Further, you can raise the issue with Debian for specific CVEs
Update:
Product group is in the middle of releasing an updated image with fixes for all the actionable Debian vulnerabilities. The expected date to be completed is next week if there are no issues.
You can rebuild your custom docker image by end of next week so you should get the updated base image.
As, some of the Debian vulnerabilities do not have patches available yet and they would remain unpatched with the new image as well.
If you have any concerns on the docker image you can always create the issue here: https://github.com/Azure/azure-functions-docker