It does look like the afl.rs project (afl for rust code) has been run on regex: https://github.com/frewsxcv/afl.rs#trophy-case https://github.com/frewsxcv/afl.

It does look like the afl.rs project (afl for rust code) has been run on regex: https://github.com/frewsxcv/afl.rs#trophy-case https://github.com/frewsxcv/afl.rs#trophy-case Which resulted in just one issue? I'm not sure how long they fuzzed or what the methodology was, but this was the panic they found (still not a memory safety issue, more akin to an unchecked exception in Java than a crash in C++): https://github.com/rust-lang/regex/issues/84 https://github.com/rust-lang/regex/issues/84 Since that issue is from the same time as Rust's 1.0 release, I suspect that either it hasn't been run again recently or that things are pretty stable in the regex crate w.r.t. fuzzing.