...
Security vulnerabilities may arise when an application expects input in a form that an adversary is capable of bypassing. This can happen when an application disregards supplementary characters or when it fails to use combining characters appropriately. Combining characters are characters that modify other characters. Refer to the Combining Diacritical Marks chart for more details on combining characters.
Coonsequently, supplementary characters and combining characters must be taken into account when operating on individual characters.
Noncompliant Code Example
...