---
id: CVE-2026-55145
title: Outlook Copilot Tampering Vulnerability
summary: >-
  Improper neutralization of special elements used in a command ('command
  injection') in Outlook Copilot allows an authorized attacker to perform
  tampering over a network.
severity: medium
cvss: 6.3
cvssVector: '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'
cvssSource: cna
cwe:
  - CWE-77
vendor: Microsoft
product: Microsoft Copilot
affected:
  - copilot -
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-14T18:49:46.518586Z'
published: '2026-07-14'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T22:33:07.756Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-55145'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55145'
    label: Outlook Copilot Tampering Vulnerability
tags:
  - cve.org
epss: 0.00525
epssPercentile: 0.43485
ingestedAt: '2026-09-08T17:06:31.908Z'
---

## 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.

## Affected

- `copilot -`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.