CVE-2026-50517
Received Received - Intake

Deserialization Flaw in M365 Copilot Permits Remote Code Execution

Publication date: 2026-07-24

Last updated on: 2026-07-24

Assigner: Microsoft Corporation

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

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Meta Information

Published
2026-07-24
Last Modified
2026-07-24
Generated
2026-07-24
AI Q&A
2026-07-24
EPSS Evaluated
N/A
NVD
CVE-2026-50517
EUVD
EUVD-2026-48457

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
microsoft m365_copilot *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-502 The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

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Executive Summary

This vulnerability involves deserialization of untrusted data in M365 Copilot. An authorized attacker can exploit this to execute arbitrary code remotely over a network.

Impact Analysis

An attacker could gain control over systems running M365 Copilot, leading to unauthorized code execution, data breaches, or further network compromise.

Compliance Impact

This vulnerability could lead to unauthorized access or data exfiltration, violating GDPR (data protection) and HIPAA (health data privacy) requirements, potentially resulting in legal penalties and reputational damage.

Mitigation Strategies

Apply the latest security updates from Microsoft for M365 Copilot immediately to patch the deserialization flaw. Disable unnecessary network access to M365 Copilot services until patched. Monitor for unusual network activity or unauthorized code execution attempts.

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