CVE-2026-119986: Microsoft Office Excel heap buffer overflow in network parsing

CVE-2026-119986 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Office Excel, a widely used spreadsheet application, contains a memory corruption vulnerability that allows attackers to execute arbitrary code when a user opens a specially crafted file. An attacker can exploit this over a network without user interaction in some configurations, potentially leading to complete system compromise and data theft.

Technologies: Microsoft Office Excel. Vendors: Microsoft.

Quick answers

Is CVE-2026-119986 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-119986 being exploited in the wild.
How severe is CVE-2026-119986?
High severity, with a CVSS score of 8.8, published 10 November 2026.
Which products and versions are affected?
Microsoft Office Excel.
Is there a fix for CVE-2026-119986?
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-2026-119986 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-119986?
Check whether you run Microsoft Office Excel. 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 Excel's parsing logic. The vulnerability can be triggered over the network to achieve remote code execution. Exploitation requires the victim to open a malicious Excel file, making this a code execution vector with moderate attack complexity.

Affected products

  • Microsoft Office Excel

Timeline

  • 2026-11-10: disclosed

References

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