PT-2026-64203 · Microsoft · M365 Copilot

CVE-2026-50517 · Published 2026-07-24 · Updated 2026-07-24

NVD

CVSS v3.1

9.9

Critical

Base vector

AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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

Fix

Deserialization of Untrusted Data

Weakness Enumeration

CWE-502

Related Identifiers

CVE-2026-50517

Affected Products

M365 Copilot

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-50517 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50517 · Vendor Advisory