CVE-2026-55043: Microsoft PowerPoint heap overflow remote code execution

CVE-2026-55043 · Severity: high · CVSS 7.8 · Published 2026-07-14

A security vulnerability has been identified in Microsoft PowerPoint, the widely used presentation software. If a user is tricked into opening a specially crafted malicious file, an attacker could gain the ability to run unauthorized code on the user's computer. This could lead to the theft of sensitive data, unauthorized changes to files, or a complete compromise of the affected system.

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 PowerPoint 2016. Vendors: Microsoft.

Quick answers

Is CVE-2026-55043 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-55043 being exploited in the wild.
How severe is CVE-2026-55043?
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 versions prior to 16.111.26071215; Microsoft Office LTSC 2021 16.0.1 and later versions prior to security updates; and 4 more.
Is there a fix for CVE-2026-55043?
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-2026-55043 attacked?
It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-55043?
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

A heap-based buffer overflow vulnerability exists in Microsoft Office PowerPoint due to improper handling of objects in memory, potentially triggered by an underlying integer overflow. The vulnerability is locally exploitable but requires user interaction, typically involving a victim opening a maliciously crafted PowerPoint file. Successful exploitation allows an attacker to execute arbitrary code in the context of the current user. Affected versions include various releases of Office 2016, 2019, LTSC 2021/2024, and Microsoft 365 Apps on both Windows and macOS. 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 versions prior 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 and later versions prior to 16.111.26071215
  • Microsoft Microsoft Office LTSC for Mac 2024 16.0.0 and later versions prior to 16.111.26071215
  • Microsoft Microsoft PowerPoint 2016 versions prior to 16.0.5561.1000

Timeline

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

References

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