Quick answers
- Is CVE-2026-102856 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-102856 being exploited in the wild.
- How severe is CVE-2026-102856?
- High severity, with a CVSS score of 8.8, published 13 October 2026.
- Which products and versions are affected?
- Microsoft Office Visio.
- Is there a fix for CVE-2026-102856?
- 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-2026-102856 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-102856?
- Check whether you run Microsoft 365 Apps, Microsoft Office 2021, Microsoft Office 2024 or one of the others listed. 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 when processing specially crafted input. The vulnerability allows remote code execution over the network without requiring prior authentication. An attacker can craft a malicious document or network message to overflow the heap buffer, achieving arbitrary code execution in the context of the Visio application.
Affected products
- Microsoft Office Visio
Timeline
- 2026-10-13: disclosed