Out-of-Bounds Read Vulnerability in Microsoft Office
CVE-2026-55139

5.5MEDIUM

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 2016
Microsoft Office 2019
Microsoft Office 365 For Mac
Vendor
CVE Published:
14 July 2026

What is CVE-2026-55139?

An out-of-bounds read vulnerability in Microsoft Office enables unauthorized attackers to potentially disclose sensitive information locally. Attackers exploiting this flaw could gain access to data that should remain secure, posing significant risks to user privacy and application integrity. Users of affected versions are advised to apply available updates promptly to mitigate potential threats.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 2016 32-bit Systems 16.0.0 < 16.0.5561.1000

Microsoft Office 2019 32-bit Systems 19.0.0

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
5.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.