---
id: CVE-2026-55005
title: >-
  Heap-based buffer overflow in Microsoft Exchange Server allows an authorized
  attacker to execute code over a network.
summary: >-
  Heap-based buffer overflow in Microsoft Exchange Server allows an authorized
  attacker to execute code over a network.
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
vendor: microsoft
product: exchange_server
affected:
  - exchange_server = 2016
  - exchange_server = 2019
  - exchange_server_subscription_edition < 15.02.2562.045
patched:
  - exchange_server_subscription_edition 15.02.2562.045
published: '2026-07-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T22:10:00.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55005'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55005'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-07-15T03:57:28.509400Z'
epss: 0.0101
epssPercentile: 0.62967
ingestedAt: '2026-09-08T17:06:31.929Z'
---

## Overview

Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execute code over a network.

## Affected

- `exchange_server = 2016`
- `exchange_server = 2019`
- `exchange_server_subscription_edition < 15.02.2562.045`

## Remediation

Upgrade past the affected range:

- `exchange_server_subscription_edition 15.02.2562.045`