---
id: CVE-2026-69378
title: >-
  Uncontrolled recursion in Microsoft Exchange Server allows an unauthorized
  attacker to deny service over a network.
summary: >-
  Uncontrolled recursion in Microsoft Exchange Server allows an unauthorized
  attacker to deny service over a network.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-674
vendor: Microsoft
product: Microsoft Exchange Server 2016 Cumulative Update 23
affected:
  - exchange_server_2016_cumulative_update_23 >= 15.01.0.0 < 15.01.2507.073
  - 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: '2026-09-08'
sourceUpdated: '2026-09-08T21:18:31.240'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-69378'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69378'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T20:41:18.591112Z'
ingestedAt: '2026-09-08T19:08:49.610Z'
epss: 0.01107
epssPercentile: 0.64413
---

## Overview

Uncontrolled recursion in Microsoft Exchange Server allows an unauthorized attacker to deny service over a network.

## Remediation

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