---
id: CVE-2026-70279
title: >-
  Improper neutralization of input during web page generation ('cross-site
  scripting') in Microsoft Exchange Server allows an unauthorized attacker to
  perform spoofing over a network.
summary: >-
  Improper neutralization of input during web page generation ('cross-site
  scripting') in Microsoft Exchange Server allows an unauthorized attacker to
  perform spoofing over a network.
severity: critical
cvss: 9.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N'
cwe:
  - CWE-79
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T23:18:06.873'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70279'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70279'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-13T19:43:29.046Z'
vendor: Microsoft
product: Microsoft Exchange Server 2016 Cumulative Update 23
affected:
  - exchange_server_2016_cumulative_update_23 >= 15.01.0.0 < 15.01.2507.077
  - exchange_server_2019_cumulative_update_14 >= 15.02.0.0 < 15.02.1544.050
  - exchange_server_2019_cumulative_update_15 >= 15.02.0.0 < 15.02.1748.055
  - exchange_server_subscription_edition_rtm >= 15.02.0.0 < 15.02.2562.056
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-13T22:08:56.698883Z'
epss: 0.01286
epssPercentile: 0.69994
---

## Overview

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.

## Remediation

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