CVE-2026-50517CWE-502

Microsoft M365 Copilot Remote Code Execution Vulnerability

Critical · published July 24, 2026

CVSS v3.1
9.9
EPSS
2%
Percentile
76.9
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
9.9 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
CVSS v4.0
Not supplied
EPSS
0.01694 · 76.9th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-07-24T00:01Z
EPSS history
Timeline
  • 24 JUL 00:01Z
    Microsoft M365 Copilot Remote Code Execution Vulnerability
    cvelistv5