---
id: CVE-2026-62911
title: Microsoft Exchange Server Elevation of Privilege Vulnerability
summary: >-
  Authentication bypass by capture-replay in Microsoft Exchange Server allows an
  authorized attacker to elevate privileges over a network.
severity: high
cvss: 8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-294
vendor: Microsoft
product: Microsoft Exchange Server 2016 Cumulative Update 23
affected:
  - exchange_server_2016_cumulative_update_23 >= 15.01.0.0 < 15.01.2507.072
  - exchange_server_2019_cumulative_update_14 >= 15.02.0.0 < 15.02.1544.044
  - exchange_server_2019_cumulative_update_15 >= 15.02.0.0 < 15.02.1748.049
  - exchange_server_subscription_edition_rtm >= 15.02.0.0 < 15.02.2562.046
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-06T00:00:00+00:00'
exploitAvailable: true
published: '2026-08-11'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T19:38:17.878Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-62911'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62911'
    label: Microsoft Exchange Server Elevation of Privilege Vulnerability
tags:
  - cve.org
  - exploit-available
epss: 0.00694
epssPercentile: 0.50996
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/hypnguyen1209/CVE-2026-62911'
  checkedAt: '2026-09-27T10:33:55.038Z'
ingestedAt: '2026-09-08T18:07:34.890Z'
---

## Overview

Authentication bypass by capture-replay in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

## Affected

- `exchange_server_2016_cumulative_update_23 >= 15.01.0.0 < 15.01.2507.072`
- `exchange_server_2019_cumulative_update_14 >= 15.02.0.0 < 15.02.1544.044`
- `exchange_server_2019_cumulative_update_15 >= 15.02.0.0 < 15.02.1748.049`
- `exchange_server_subscription_edition_rtm >= 15.02.0.0 < 15.02.2562.046`

## Remediation

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