CVE-2026-78501

Microsoft 365 Copilot Business Chat Information Disclosure Vulnerability

State: Published
Severity: 8.6 High
Published: Sep 17, 2026
Updated: Oct 31, 2026
Reserved: Aug 24, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	8.6 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C	microsoft

Weaknesses

CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection')
CWE-923 Improper Restriction of Communication Channel to Intended Endpoints

Affected Products

Product	Versions
Microsoft 365 Copilot's Business ChatMicrosoft	-Affected

References

Microsoft 365 Copilot Business Chat Information Disclosure Vulnerabilityvendor-advisorypatch

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