CVE-2026-5450: glibc: glibc: Heap Buffer Overflow in `scanf` with `%mc` format specifier and large width

Severity: Critical

CVSS Score: 9.8

Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.