CVE-2026-73523: COVESA Open1722 0.9.2 Stack Memory Disclosure via acf-can-listener.c Integer Truncation

COVESA Open1722 through 0.9.2 contains an integer truncation vulnerability in acf-can-listener.c that allows unauthenticated remote attackers to cause the CAN listener to transmit process stack memory onto the CAN bus by sending a rejected UDP datagram with a matching AVTP stream ID. The numcanmsgs variable declared as uint8t truncates the -1 error return value from avtptocan() to 255, causing a write loop to iterate 255 times over a 15-slot stack array and leak approximately 18 KB of adjacent stack memory as roughly 240 CAN frames to any recipient on the CAN bus.