Information Disclosure Vulnerability in Microsoft Word Copilot
CVE-2026-21521

7.4HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Word Copilot
Vendor
CVE Published:
22 January 2026

What is CVE-2026-21521?

An information disclosure vulnerability exists in Microsoft Word Copilot due to improper neutralization of escape, meta, or control sequences. This flaw could be exploited by an unauthorized attacker to reveal sensitive information across a network, potentially compromising the confidentiality of user data. It is essential for users and organizations to apply the necessary patches and updates to mitigate the risk associated with this vulnerability.

Affected Version(s)

Microsoft 365 Word Copilot -

References

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

CVSS V3.1

Score:
7.4
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.