CVE-2026-26164
Microsoft 365 Copilot Injection Vulnerability Exposes Data
Publication date: 2026-05-07
Last updated on: 2026-05-08
Assigner: Microsoft Corporation
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| microsoft | 365_copilot_chat | * |
Helpful Resources
Exploitability
| 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. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
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.
How can this vulnerability impact me? :
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.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
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.