This trivially can't happen in WUFFS. Forget RCE, WUFFS can't even do a traditional Hello World program because (1) you can't do I/O in WUFFS and (2) the language doesn't have strings.
Very few languages can prevent you writing something like "if(text == "shibboleth") rootshell();" but most languages don't make it trivial to write accidentally.
Pretty much any memory managed language? Java, Go, Rust, Python, pretty much anything other than C/C++ these days is memory safe for security purposes.
Even C and C++ can be memory-safe if you need them to [1], but is arbitrary code execution strictly about memory safety only?
[1] https://fil-c.org/
In the sense `jeffbee meant, yes.
I don’t see them providing any kind of reasoning behind their dismissal here, but if perchance you meant `cowlevel`, then I understand and thank you for the clarification!