Approach to address security in white labelled software?

I just started working with a business that made a web application that has a nodejs-expressjs backend api and a react front end. The business wants to sell its software as a white label solution to some enterprise sized businesses. My manager says that the customers will be expecting a detailed report to convince them that our solution is "secure". I need to determine steps to producing such a security report.

My first thoughts are to follow these steps:

1. Run the npm audit command on our backend and front end projects to identify all known vulnerabilities. And then fixed them according to recommended approaches I read about on the internet. This step has been done. The npm audit command shows no vulnerabilities or issues of any kind.

2. We upload our code as docker images to dockerhub.com. Dockerhub shows a list of vulnerabilities for us to address. I am currently in this step, and I have some issues which I will elaborate further down in this post.

3. Hire a 3rd party cyber security firm to test our solution. This firm will give us a report of issues to address.

That's my overall plan. However, I am currently stuck on step 2. Dockerhub is showing me MANY Critical and High priority vulnerabilities such as the following:

• cve-2021-44906 - An Uncontrolled Resource Consumption flaw was found in minimist
  https://access.redhat.com/security/cve/cve-2021-44906

• CVE-2022-37434 - zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field.
  https://nvd.nist.gov/vuln/detail/CVE-2022-37434

...etc...

According to dockerhub, there are about 100 of these types of vulnerabilities, where maybe 10% are critical, 15% are high, rest are medium or low. These issues look very difficult to address, because they are used by modules of modules that I don't directly access in my own software. Trying to replace these modules of modules basically means a complete rewrite of our software to not depend on ANY open source solutions at all! And I'm sure if I were to scan packages with another type of scanner, different sets of vulnerabilities would be exposed. And I haven't even gotten to step 3 yet.

So this got me wondering...how do other organizations selling white labelled solutions go about disclosing vulnerabilities to their end clients and how do they protect themselves?

I started thinking that maybe I don't have to deal with every single security vulnerability that exists. Instead, I should only address security issues that I am confident hackers will exploit or things that are easy to address. Then I hire a security party firm to find other vulnerabilities. Anything that's not caught by the security firm we deem as "not important". And we develop some contract and service agreement that protects our business from the legal actions if our clients experiences a security vulnerability not covered in our report?

But then, a customer will say, "But dockerhub.com clearly shows vulnerability X, and you as the seller were aware of vulnerability X, please justify to us why you did not address it." And how do we respond then?

That's what's in my head right now.

So back to my original question - what steps should a team take to address security concerns of a software that will be white labelled and sold to customers?