CVE-2026-50517

CRITICAL

Microsoft M365 Copilot Remote Code Execution Vulnerability

Title source: cna
STIX 2.1

Description

Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory patch
Microsoft M365 Copilot Remote Code Execution Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50517

Scores

CVSS v3 9.9
EPSS 0.0125
EPSS Percentile 66.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-502
Status published
Products (2)
microsoft/365_copilot
Microsoft/Microsoft 365 Copilot -
Published Jul 24, 2026
Tracked Since Jul 24, 2026