I tested screen with the compiler feature Address Sanitizer (-fsanitize=address in CFLAGS/LDFLAGS). When running screen on a real Linux console (not in an X terminal) it didn't start due to an error.

The error can't be seen directly because screen disables stderr, to reproduce it one can use ASAN_OPTIONS="log_path=[somepath]".

The problem is this code in termcap.c:
                s = "l+m+k+j+u+t+v+w+q-x|n+o~s_p\"r#`+a:f'g#~o.v-^+<,>h#I#0#y<z>";
                for (i = strlen(s) & ~1; i >= 0; i -= 2)
                        D_c0_tab[(int)(unsigned char)s[i]] = s[i + 1];

The loop will start right of the string s. One needs to substract 2 from strlen(s) for the code to be correct. Right after that is a loop with the same logic, so the same fix should be applied. I will attached a patch that fixes both.

Will also attach the address sanitizer error message.