CVE-2026-26164
Modified Modified - Updated After Analysis
Microsoft 365 Copilot Injection Vulnerability Exposes Data

Publication date: 2026-05-07

Last updated on: 2026-06-01

Assigner: Microsoft Corporation

Description
Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to disclose information over a network.
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Meta Information
Published
2026-05-07
Last Modified
2026-06-01
Generated
2026-06-19
AI Q&A
2026-05-08
EPSS Evaluated
2026-06-18
NVD
CVE-2026-26164
EUVD
EUVD-2026-28446
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
microsoft 365_copilot_chat *
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-74 The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
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Executive Summary

This vulnerability involves improper neutralization of special elements in output used by a downstream component, which is a type of injection flaw in Microsoft 365 Copilot. It allows an unauthorized attacker to disclose information over a network.

Impact Analysis

The vulnerability can lead to unauthorized disclosure of sensitive information over a network, potentially exposing confidential data to attackers without requiring any privileges or user interaction.

Compliance Impact

This vulnerability in M365 Copilot allows an unauthorized attacker to disclose information over a network due to improper neutralization of special elements in output used by a downstream component.

Such unauthorized information disclosure could potentially impact compliance with data protection regulations like GDPR and HIPAA, which require safeguarding sensitive information against unauthorized access and disclosure.

However, specific details on how this vulnerability affects compliance with these standards are not provided.

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