CVE-2025-12875 — Improper Restriction of Operations within the Bounds of a Memory Buffer in Mruby

A weakness has been identified in mruby 3.4.0. This vulnerability affects the function ary_fill_exec of the file mrbgems/mruby-array-ext/src/array.c. Executing a manipulation of the argument start/length can lead to out-of-bounds write. The attack needs to be launched locally. The exploit has been made available to the public and could be used for attacks. This patch is called 93619f06dd378db6766666b30c08978311c7ec94. It is best practice to apply a patch to resolve this issue.