What is CVE-2026-78501?

CVE-2026-78501 is a security advisory published by Microsoft Security Response Center (MSRC) with Critical severity. Microsoft 365 Copilot Business Chat Information Disclosure Vulnerability

Which CVE IDs does CVE-2026-78501 cover?

CVE-2026-78501 covers the following CVE IDs: CVE-2026-78501. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-78501?

CVE-2026-78501 has a CVSS v3 base score of 7.4, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-78501?

CVE-2026-78501 affects 1 product, including: Microsoft 365 Copilot's Business Chat.

CVE-2026-78501CriticalCVSS 7.4

Microsoft 365 Copilot Business Chat Information Disclosure Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

September 17, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-78501 →

📋 Description

Improper neutralization of special elements used in a command ('command injection') in Microsoft 365 Copilot's Business Chat allows an unauthorized attacker to disclose information over a network.

🎯 Affected products1

Microsoft 365 Copilot's Business Chat

🔗 References (1)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78501