CVE intelligenceCISA KEV

CVE-2026-42897

Microsoft Exchange Server Cross-Site Scripting Vulnerability

Published May 14, 2026Sources checked Nov 12, 2026

6.1MEDIUMCVSS out of 10

What this means

Actively exploited

CISA lists CVE-2026-42897 in its Known Exploited Vulnerabilities catalog, which means exploitation has been observed. The entry applies to Microsoft Microsoft.

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public exploit: Not collected.

Microsoft Security Response Center: Exploitation reported by Microsoft Security Response Center (2026-07-14)
Microsoft exploitation status: Exploited:Yes

What to do next

Remediation and response

Review the linked vendor advisory and apply the mitigation or fixed release for your affected product.

Microsoft Security Response Center guidance

Vendor revision: Jul 14, 2026

Vendor remediation details

Install KB5094144. Install KB5094142. Install KB5094140. Install KB5094139.

Vendor-listed releases

15.01.2507.069
15.02.1544.041
15.02.1748.046
15.02.2562.043

CISA KEVListedObserved exploitation

EPSS70.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-42897?

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.

Source: NVD

Reported activity: Microsoft exploitation status: Exploited:Yes
Microsoft Security Response Center · Published Jul 14, 2026

CISA says:Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.CISA catalog due date May 29, 2026