CVE-2026-42897

Name: CVE-2026-42897
Creator: NVD / NIST
Published: 2026-05-14T18:16:49.36+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10Actively ExploitedEPSS 5.64%

Last modified Jun 17, 2026

CVE-2026-42897 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 5.64% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

5.64%

92.0th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by May 29, 2026.

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Microsoft	Exchange Server	2016
Microsoft	Exchange Server	2019
Microsoft	Exchange Server Subscription Edition	< 15.02.2562.043

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42897Mitigation, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-42897US Government Resource

Timeline

Published: May 14, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

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.

How severe is CVE-2026-42897?

CVE-2026-42897 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 5.64% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2026-42897?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-42897?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST