Outlook Copilot Tampering Vulnerability
Published July 14, 2026Updated July 14, 2026
Source data
Overview
Improper neutralization of special elements used in a command ('command injection') in Outlook Copilot allows an authorized attacker to perform tampering over a network.
Impact & technical details
Tampering
How do I protect myself from this vulnerability? Customers can help protect themselves by enabling Outlook's external sender tagging feature to identify untrusted content. This enables Microsoft's provided mitigations to isolate and safely process the untrusted content before it is provided to Microsoft 365 Copilot. Administrators can enable external sender tagging through Exchange Online PowerShell. Refer to the Microsoft Learn documentation for setup instructions and requirements. Install the Exchange Online PowerShell Module Connect to Exchange Online PowerShell Set-ExternalInOutlook
- CVSS base score
- 6.3 / 10
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N/E:P/RL:O/RC:C
Highest base score supplied by MSRC for this record; the vector belongs to that score. Ratings can vary by product. Microsoft Important is displayed as High; Moderate is displayed as Medium.
Affected products
- Microsoft Copilot
Source guidance
Remediation
The source provides update references without a separate remediation summary. Review the applicable update links below.
Patch availability is not confirmed by this dataset. Consult the vendor before selecting a remediation.
GTP recommendation · Rule-based guidance
Recommended next step
Review affected Microsoft products and apply the applicable security updates through your organization's normal patch-management process. Confirm availability and prerequisites in the Microsoft advisory.
Authoritative sources & updates
Findings and update information come from the linked publishers. GTP compiles the public record and provides the recommendation above. CVSS ratings shown here come from Microsoft. NVD references provide additional public context.
Managed by GTP?
Griffin Technology Partners managed customers may receive additional environment-specific security guidance and remediation assistance through their managed services relationship.
Security bulletins are provided for informational purposes and compiled from authoritative public sources. Vulnerability applicability varies by environment. Validate affected products, configuration, compatibility requirements, and vendor guidance before making production changes.