CVE-2026-78501

High CVSS 7.4

Published 2026-09-17 · last changed 2026-09-18

The fix

We hold no Microsoft remediation data for CVE-2026-78501, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

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.

Sources

NVD record for CVE-2026-78501

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N