Your question is Handling a Critical Production Bug. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You are working as a QA engineer on a regulated healthcare software product, and during validation you uncover a critical bug that could affect a core user workflow. The issue appears late in the release cycle, so there is pressure to avoid delaying the release, but the defect may have patient safety, compliance, and customer impact if mishandled.
Can you describe a time when you found a critical bug in a product? How did you handle it?