What is CVE-2026-26164?

CVE-2026-26164 is a security advisory published by Microsoft Security Response Center (MSRC) with Information Disclosure severity. M365 Copilot Information Disclosure Vulnerability

Which CVE IDs does CVE-2026-26164 cover?

CVE-2026-26164 covers the following CVE IDs: CVE-2026-26164. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-26164?

CVE-2026-26164 has a CVSS v3 base score of 7.5, published by Microsoft Security Response Center (MSRC).

CVE-2026-26164Information DisclosureCVSS 7.5

M365 Copilot Information Disclosure Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

May 22, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-26164 →

📋 Description

<p>Improper neutralization of special elements in output used by a downstream component ('injection') in M365 Copilot allows an unauthorized attacker to disclose information over a network.</p>