CVE-2026-109494: Microsoft Office Visio heap buffer overflow

CVE-2026-109494 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Office Visio, a diagramming and visualization tool used by businesses, contains a heap-based buffer overflow vulnerability. An attacker could exploit this flaw by sending a specially crafted file over the network to execute arbitrary code on a victim's computer, potentially leading to data theft, system compromise, or ransomware infection.

Technologies: Microsoft Office Visio. Vendors: Microsoft.

Quick answers

Is CVE-2026-109494 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-109494 being exploited in the wild.
How severe is CVE-2026-109494?
High severity, with a CVSS score of 8.8, published 10 November 2026.
Which products and versions are affected?
Microsoft Office Visio.
Is there a fix for CVE-2026-109494?
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-2026-109494 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-109494?
Check whether you run Microsoft Office Visio. 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

A heap-based buffer overflow exists in Microsoft Office Visio that can be triggered by processing a malicious file. The vulnerability is reachable over the network without requiring prior authentication or user interaction beyond opening a file. Successful exploitation allows remote code execution with the privileges of the user running Visio.

Affected products

  • Microsoft Office Visio

Timeline

  • 2026-11-10: disclosed

References

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