CVE-2026-85644 is a type confusion vulnerability in XS::Parse::Infix versions 0.40 through 0.49 for Perl. The vulnerability arises because the wrapper function incorrectly checks argument types, leading to dereferencing invalid memory and causing a segmentation fault. This can be triggered by supplying crafted input, such as a number treated as an array reference, potentially allowing an attacker to control memory dereferencing.