musl libc 0.9.13 through 1.2.5 before 1.2.6 has an out-of-bounds write vulnerability when an attacker can trigger iconv conversion of untrusted EUC-KR text to UTF-8.
In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).