CVE-2026-63521: Microsoft Office Word Information Disclosure Vulnerability
Published Aug 11, 2026
·Updated
Microsoft Office Word Information Disclosure Vulnerability
Other sources
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
— Microsoft
Affected Software
12 affected componentsFixes available
Microsoft 365 Apps
Microsoft 365 Apps
Microsoft Office 2019
Microsoft Office 2019
Microsoft Office 2021
Microsoft Office 2021
Microsoft Office 2024
Microsoft Office 2024
Microsoft Word=2016
Microsoft Word=2016
Microsoft Word 2016<16.0.5565.1000
16.0.5565.1000
Microsoft Word 2016<16.0.5565.1000
16.0.5565.1000
Remediation
Event History
Aug 11, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
CVE Published
via MITRE·05:04 PM
Data Sourced
via MITRE·05:04 PM
DescriptionSeverity
Data Sourced
via NVD·05:18 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-63521?
The severity of CVE-2026-63521 is medium with a score of 5.5.
2
How do I fix CVE-2026-63521?
To fix CVE-2026-63521, ensure that you update Microsoft Office Word to the latest version provided by Microsoft.
3
What type of vulnerability is CVE-2026-63521?
CVE-2026-63521 is an information disclosure vulnerability due to an out-of-bounds read.
4
Who is affected by CVE-2026-63521?
CVE-2026-63521 affects Microsoft Office Word 2016, Microsoft 365 Apps for Enterprise, and various versions of Microsoft Office LTSC and Office 2019.
5
What does CVE-2026-63521 allow an attacker to do?
CVE-2026-63521 allows an unauthorized attacker to disclose information locally.