The question is whether proportionally more bugs are found, and the indications are yeah, a lot more. There was an academic study of bugs in the Firefox codebas

The question is whether proportionally more bugs are found, and the indications are yeah, a lot more. There was an academic study of bugs in the Firefox codebase and they found that first time contributors were far more likely to introduce bugs in C++ than Rust proportionally, with the ratio getting tighter as people have more experience with the codebase. If you've got a team of people who've lived with your C++ codebase for a decade, they're perhaps not introducing more bugs than they would in Rust. You're looking at a list of less than two dozen CVEs over several years across the Rust standard library and tooling. There are no CVEs raised for the analogous C++ behaviour, it's just accepted as normal.