Information Disclosure Vulnerability in M365 Copilot by Microsoft
CVE-2026-26164

7.5HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Copilot's Business Chat
Vendor
CVE Published:
7 May 2026

What is CVE-2026-26164?

An information disclosure vulnerability exists in M365 Copilot due to improper neutralization of special elements in output. This flaw may allow unauthorized attackers to expose sensitive information over a network, potentially compromising data integrity and privacy for users of the affected product.

Affected Version(s)

Microsoft 365 Copilot's Business Chat -

References

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

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.