---
title: "CVE-2026-70279: Microsoft Exchange Server - Stored XSS"
description: "Microsoft Exchange Server contains a stored XSS caused by improper neutralization of input during web page generation, letting unauthorized attackers perform spoofing over a network, exploit requires no special conditions."
url: https://panop.io/threat-heartbeat/CVE-2026-70279/
---

# CVE-2026-70279 Microsoft Exchange Server - Stored XSS

Microsoft Exchange Server contains a stored XSS caused by improper neutralization of input during web page generation, letting unauthorized attackers perform spoofing over a network, exploit requires no special conditions.

CVSS base score 9.3 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.86% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-70279)

## Details

Type

Stored XSS

Impact

Stored XSS

CVSS vector

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

Published

13 October 2026

Updated

15 October 2026

Weakness

[CWE-79](https://cwe.mitre.org/data/definitions/79.html)

## Vendor fix

Update to the latest version of Microsoft Exchange Server.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-70279](https://nvd.nist.gov/vuln/detail/CVE-2026-70279)
- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70279](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70279)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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