CVE-2026-55132: Microsoft Office Word double free local code execution

CVE-2026-55132 · Severity: high · CVSS 7.8 · Published 2026-07-14

A security vulnerability has been identified in Microsoft Office Word and related SharePoint server components. This flaw could allow an attacker to execute malicious code on a user's computer if the user is tricked into opening a specially crafted file. Successful exploitation could lead to a full compromise of the affected system, potentially resulting in data theft or unauthorized access to corporate resources.

Technologies: Microsoft 365 Apps for Enterprise, Microsoft Office 2019, Microsoft Office 365 for Mac, Microsoft Office LTSC 2021, Microsoft Office LTSC 2024, Microsoft Office LTSC for Mac 2021, Microsoft Office LTSC for Mac 2024, Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition. Vendors: Microsoft.

Quick answers

Is CVE-2026-55132 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-55132 being exploited in the wild.
How severe is CVE-2026-55132?
High severity, with a CVSS score of 7.8, published 14 July 2026.
Which products and versions are affected?
Microsoft 365 Apps for Enterprise 16.0.1 and later versions prior to security updates; Microsoft Office 2019 19.0.0 and later versions prior to security updates; Microsoft Office 365 for Mac 1.0.0 to 16.111.26071215; Microsoft Office LTSC 2021 16.0.1 and later versions prior to security updates; and 6 more.
Is there a fix for CVE-2026-55132?
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-2026-55132 attacked?
It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-55132?
Check whether you run Microsoft 365 Apps for Enterprise, Microsoft Office 2019, Microsoft Office 365 for Mac or one of the others listed 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.

Technical details

This vulnerability is classified as a double free (CWE-415) within Microsoft Office Word. The flaw occurs when the application attempts to free the same memory location twice, which can be leveraged by an attacker to corrupt memory and achieve arbitrary code execution. The attack vector is local, requiring a user to open a malicious document (User Interaction: Required). The vulnerability affects multiple versions of Microsoft Office on both Windows and macOS, as well as several SharePoint Server editions. Microsoft has released security updates to address this issue.

Affected products

  • Microsoft Microsoft 365 Apps for Enterprise 16.0.1 and later versions prior to security updates
  • Microsoft Microsoft Office 2019 19.0.0 and later versions prior to security updates
  • Microsoft Microsoft Office 365 for Mac 1.0.0 to 16.111.26071215
  • Microsoft Microsoft Office LTSC 2021 16.0.1 and later versions prior to security updates
  • Microsoft Microsoft Office LTSC 2024 16.0.0 and later versions prior to security updates
  • Microsoft Microsoft Office LTSC for Mac 2021 16.0.1 to 16.111.26071215
  • Microsoft Microsoft Office LTSC for Mac 2024 16.0.0 to 16.111.26071215
  • Microsoft Microsoft SharePoint Enterprise Server 2016 16.0.0 to 16.0.5561.1001
  • Microsoft Microsoft SharePoint Server 2019 16.0.0 to 16.0.10417.20175
  • Microsoft Microsoft SharePoint Server Subscription Edition All versions prior to security updates

Timeline

  • 2026-07-14: disclosed
  • 2026-07-14: advisory

References

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