CVE-2026-71266 Details

A stack buffer overflow vulnerability has been identified in tinyobjloader-c, specifically within the function tinyobj_parse_and_index_mtl_file() in tinyobj_loader_c.h. This vulnerability arises because the function reads lines from a .mtl material file into a fixed 4096-byte stack buffer named linebuf, using memcpy. The operation is only partially safeguarded by an assertion that the length of the input line is less than 4095 bytes. In release builds, this assertion is disabled, allowing a crafted .mtl file to overflow linebuf and corrupt adjacent stack variables, including namebuf. This exploitation can disrupt the stack of any application that processes attacker-controlled 3D model or material files.