CVE-2026-50517
Microsoft M365 Copilot Remote Code Execution Vulnerability
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Microsoft M365 Copilot Remote Code Execution Vulnerability
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.
- Record
CVE-2026-50517- CVSS 3.1
- 9.9 Critical
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 - Weakness
- CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2026-48457
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.
- Record
EUVD-2026-48457- CVSS 3.1
- 9.9 Critical
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-cfm3-7vpc-px47
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code...
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.
- Record
GHSA-cfm3-7vpc-px47- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
NVD
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.
- Record
CVE-2026-50517- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-50517 is a critical vulnerability (CVSS 9.9) in Microsoft 365 Copilot, published July 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.69%, the 77th percentile. No source names a fixed version.