syoyo tinyobjloader-c tinyobj_loader_c.h tinyobj_parse_and_index_mtl_file stack-based overflow

Summaryinfo

A vulnerability described as critical has been identified in syoyo tinyobjloader-c. This vulnerability affects the function tinyobj_parse_and_index_mtl_file of the file tinyobj_loader_c.h. The manipulation results in stack-based overflow. This vulnerability is reported as CVE-2026-71266. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, was found in syoyo tinyobjloader-c (unknown version). Affected is the function tinyobj_parse_and_index_mtl_file of the file tinyobj_loader_c.h. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-71266 since 08/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/05/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• syoyo

Name

• tinyobjloader-c

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion