A stack-based buffer overflow in the motion_privacy.cgi binary in VIVOTEK FD8136 firmware FD8136-VVTK-0300a allows authenticated remote attackers to execute arbitrary code as root via an oversized n1 parameter in a POST request to the /cgi-bin/admin/setpm.cgi, /cgi-bin/admin/setmd.cgi, or /cgi-bin/admin/setmd_profile.cgi endpoint (all symlinks to the same binary). The parameter value is copied into a fixed-size 0xa4-byte stack buffer without bounds checking, overwriting the saved link register. The binary is compiled without stack canaries.