CVE-2026-112739: Microsoft Office Word heap buffer overflow

CVE-2026-112739 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Office Word, a widely-used document editing application, contains a heap buffer overflow flaw that allows an attacker to execute arbitrary code on a user's computer. An attacker can exploit this vulnerability by sending a specially crafted document over the network, potentially gaining complete control of the affected system without requiring user authentication.

Technologies: Microsoft Office Word. Vendors: Microsoft.

Quick answers

Is CVE-2026-112739 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-112739 being exploited in the wild.
How severe is CVE-2026-112739?
High severity, with a CVSS score of 8.8, published 10 November 2026.
Which products and versions are affected?
Microsoft Office Word.
Is there a fix for CVE-2026-112739?
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-2026-112739 attacked?
It is attacked over the network.
Am I affected by CVE-2026-112739?
Check whether you run Microsoft Office Word. 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 in Microsoft Office Word's document parsing logic allows an attacker to corrupt heap memory and redirect execution flow. The vulnerability is triggered when processing a malicious Word document delivered over a network, with no user authentication required—only that the victim opens the crafted file. Successful exploitation results in arbitrary code execution with the privileges of the Word process.

Affected products

  • Microsoft Office Word

Timeline

  • 2026-11-10: disclosed

References

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