Starliner (I assume that's what you mean by CST) is pure Boeing, not ULA. It's also worth mentioning that ULA's probably about to be sold [1]; the three potential buyers are Blue Origin, the private equity fund Cerberus [2], and the aerospace contractor Textron.

[1] https://arstechnica.com/space/2023/11/sale-of-united-launch-...

[2] https://www.wsj.com/business/billionaires-compete-to-own-spa...