# CVE-2026-19970: Assimp MDLImporter heap-based buffer overflow in AddBonesToNodeGraph

Source: https://junglewise.ai/threats/cve-2026-19970-assimp-mdlimporter-heap-based-buffer-overflow-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-17. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-19970 · Severity: medium · CVSS 6.3 · Published 2026-08-17

Assimp is an open-source library used to import and process 3D model files in game engines and graphics applications. A heap-based buffer overflow vulnerability in the MDL model parser allows an attacker to overflow memory by crafting a malicious 3D model file, potentially leading to crashes, memory corruption, or arbitrary code execution when the file is loaded and processed.

Technologies: [Assimp](https://junglewise.ai/threats/technologies/assimp). Vendors: [Assimp](https://junglewise.ai/threats/vendors/assimp).

## Quick answers

**Is CVE-2026-19970 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-19970 being exploited in the wild.

**How severe is CVE-2026-19970?** Medium severity, with a CVSS score of 6.3, published 17 August 2026.

**Which products and versions are affected?** Assimp commit 17c12da and likely other versions.

**Is there a fix for CVE-2026-19970?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-19970 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-19970?** Check whether you run Assimp at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a heap-based buffer overflow in the MDLImporter::AddBonesToNodeGraph_3DGS_MDL7 function within MDLLoader.cpp. The flaw is triggered by improper validation of the bones_num argument when parsing MDL (Quake engine) model files, allowing an attacker to write beyond allocated memory bounds. The attack requires an attacker to craft and serve a malicious MDL file; exploitation occurs when a victim application loads the file using Assimp. The attack is remotely exploitable with no authentication required, though it does require a user or application to explicitly load a crafted model file. A public proof-of-concept exploit is available. At time of disclosure, the Assimp project had not released a patch.

## Affected products

- Assimp Assimp commit 17c12da and likely other versions

## Timeline

- 2026-08-17: disclosed: CVE-2026-19970 published on NVD
- 2026-08-17: advisory: Public proof-of-concept exploit released

## References

- [https://github.com/assimp/assimp/issues/6632](https://github.com/assimp/assimp/issues/6632)
- [https://github.com/user-attachments/files/27428677/poc.zip](https://github.com/user-attachments/files/27428677/poc.zip)

## Related threats

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- [Assimp MDL importer heap buffer overflow](https://junglewise.ai/threats/cve-2026-19969-assimp-mdl-importer-heap-buffer-overflow)
- [Assimp heap buffer overflow in LWO2 model parser](https://junglewise.ai/threats/cve-2026-19968-assimp-heap-buffer-overflow-in-lwo2-model-parser)
- [Assimp out-of-bounds read in HL1MDLLoader](https://junglewise.ai/threats/cve-2026-10233-assimp-out-of-bounds-read-in-hl1mdlloader)