CVE-2026-70279Network attack vector

Unauthenticated spoofing via cross-site scripting

Published Oct 13, 2026 · Updated Oct 13, 2026

Cross-site scripting in Microsoft Exchange Server allows remote attackers to perform spoofing through network-accessible web content. The CNA identifies improper input neutralization during page generation but does not name the affected endpoint or operation; its sole vendor reference was inaccessible. Exploitation requires user interaction, with confidentiality and integrity impacts but no reported service interruption.

CVSS severity9.3
Critical
EPSS probability0.86%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Microsoft Exchange Server allows remote attackers to perform spoofing through network-accessible web content. The CNA identifies improper input neutralization during page generation but does not name the affected endpoint or operation; its sole vendor reference was inaccessible. Exploitation requires user interaction, with confidentiality and integrity impacts but no reported service interruption.

The record

CVE
CVE-2026-70279
Published
Oct 13, 2026
Updated
Oct 13, 2026
Vendor
Microsoft Corporation
Product
Microsoft Exchange Server 2019 Cumulative Update 14
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.02.0.0 <15.02.1544.050

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft Corporation · Microsoft Exchange Server 2019 Cumulative Update 14version=15.02.0.0 <15.02.1544.050
Microsoft Corporation · Microsoft Exchange Server Subscription Edition RTMversion=15.02.0.0 <15.02.2562.056
Microsoft Corporation · Microsoft Exchange Server 2016 Cumulative Update 23version=15.01.0.0 <15.01.2507.077
Microsoft Corporation · Microsoft Exchange Server 2019 Cumulative Update 15version=15.02.0.0 <15.02.1748.055

Published CVSS scores

9.3MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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