# CVE-2026-9536: VTK vtkWindBladeReader heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-9536-a-heap-based-buffer-overflow-vulnerability-exists-in-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-9536 · Severity: high · CVSS 7.5 · Published 2026-10-29

VTK is an open-source 3D visualization and scientific computing toolkit used in research and engineering applications. The vtkWindBladeReader component parses wind simulation data files, and contains a heap buffer overflow vulnerability when processing malformed .wind metadata files. An attacker can craft a malicious data file to trigger a denial-of-service crash or potentially achieve arbitrary code execution.

Technologies: [Kitware VTK](https://junglewise.ai/threats/technologies/kitware-vtk). Vendors: [Kitware](https://junglewise.ai/threats/vendors/kitware).

## Quick answers

**Is CVE-2026-9536 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9536 being exploited in the wild.

**How severe is CVE-2026-9536?** High severity, with a CVSS score of 7.5, published 29 October 2026.

**Which products and versions are affected?** Kitware VTK 9.6.1.

**Is there a fix for CVE-2026-9536?** Yes: fixed in 9.6.2, 9.7.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-9536 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-9536?** Check whether you run Kitware VTK 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.

## How to fix

- Fixed in 9.6.2, 9.7.1

## Technical details

A heap-based buffer overflow exists in the FindVariableOffsets function, where an attacker-controlled signed integer (byteCount) from the binary data file is cast to size_t without validation. Values between -3 and 3 result in a zero-sized buffer allocation, while the code later reads beyond this allocation based on grid dimensions from the metadata file. The vulnerability requires a specially crafted .wind file pair (ASCII metadata + binary data) to trigger.

## Affected products

- Kitware VTK 9.6.1

## Timeline

- 2026-10-29: disclosed

## References

- [https://talosintelligence.com/vulnerability_reports/TALOS-2026-2424](https://talosintelligence.com/vulnerability_reports/TALOS-2026-2424)
- [https://vtk.org/download/](https://vtk.org/download/)

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