tinyobjloader-c's tinyobj_parse_and_index_mtl_file (tinyobj_loader_c.h) reads each line of a .mtl material file into a fixed 4096-byte stack buffer via memcpy(linebuf, p, p_len), guarded only by . The identical vulnerable pattern is duplicated in a second function in the same file.

tinyobjloader-c's tinyobj_parse_and_index_mtl_file() (tinyobj_loader_c.h) reads each line of a .mtl material file into a fixed 4096-byte stack buffer `linebuf` via memcpy(linebuf, p, p_len), guarded only by `assert(p_len < 4095)`. Because assert() compiles to a no-op under -DNDEBUG (standard for release builds), a crafted .mtl file containing a line (e.g. a "newmtl" material name) longer than 4096 bytes overflows linebuf into the adjacent stack variable namebuf and beyond, corrupting the stack of any application that loads attacker-supplied 3D model/material files. The identical vulnerable pattern is duplicated in a second function in the same file.

Affected: Ubuntu:18.04:LTS: goxel, Ubuntu:20.04:LTS: goxel, Ubuntu:22.04:LTS: goxel, Ubuntu:24.04:LTS: goxel, Ubuntu:26.04:LTS: goxel

tinyobjloader-c's tinyobj_parse_and_index_mtl_file (tinyobj_loader_c.h) reads each line of a .mtl material file into a fixed 4096-byte stack buffer via memcpy(linebuf, p, p_len), guarded only by . The identical vulnerable pattern is duplicated in a second function in the same file.