Type Confusion Vulnerability in Microsoft Office Excel
CVE-2025-59231

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Office Online Server
Microsoft Office 2019
Microsoft 365 Apps For Enterprise
Microsoft Office Ltsc For Mac 2021
Vendor
CVE Published:
14 October 2025

What is CVE-2025-59231?

A security flaw in Microsoft Office Excel allows for type confusion, which can enable unauthorized attackers to execute arbitrary code on a user's system. This vulnerability occurs due to improper validation of resource access types, leading to potential exploitation if a malicious document is opened. Users are encouraged to apply available patches and updates to mitigate risks associated with this issue.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Excel 2016 32-bit Systems 16.0.0.0 < 16.0.5522.1000

Microsoft Office 2019 32-bit Systems 19.0.0

References

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

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
.