CVE-2026-55145 Details
Description
Improper neutralization of special elements used in a command ('command injection') in Outlook Copilot allows an authorized attacker to perform tampering over a network.
A command injection vulnerability has been identified in Microsoft Outlook Copilot. This issue allows an authorized attacker to manipulate data over the network. The vulnerability arises from improper neutralization of special elements used in commands, which could be exploited to perform unauthorized actions or modifications.
Users can enable Outlook's external sender tagging feature to identify and safely process untrusted content before it reaches Microsoft 365 Copilot. This can be done through Exchange Online PowerShell. Instructions for installing the Exchange Online PowerShell Module, connecting to Exchange Online PowerShell, and using the Set-ExternalInOutlook command are available in the Microsoft Learn documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 14, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55145 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-77 | Improper Neutralization of Special Elements used in a Command ('Command Injection') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| microsoft copilot | All versions |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 22, 2026 | Initial Analysis | [email protected] |
| Jul 14, 2026 | CVE Modified | CISA-ADP |
| Jul 14, 2026 | New CVE Received | [email protected] |