---
id: CVE-2026-55007
title: >-
  Double free in Microsoft Exchange Server allows an unauthorized attacker to
  execute code over a network.
summary: >-
  Double free in Microsoft Exchange Server allows an unauthorized attacker to
  execute code over a network.
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-415
vendor: Microsoft
product: Microsoft Exchange Server 2019 Cumulative Update 14
affected:
  - exchange_server_2019_cumulative_update_14 >= 15.02.0.0 < 15.02.1544.046
  - exchange_server_2019_cumulative_update_15 >= 15.02.0.0 < 15.02.1748.051
  - exchange_server_subscription_edition_rtm >= 15.02.0.0 < 15.02.2562.049
published: '2026-09-08'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T10:17:06.033'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55007'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-09T04:20:19.366481Z'
ingestedAt: '2026-09-08T18:07:34.935Z'
epss: 0.00726
epssPercentile: 0.52712
---

## Overview

Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.

## Remediation

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