CVE-2026-42897

UNKNOWNKnown Exploited

CISA Known Exploited Vulnerability

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-42897 ; https://learn.microsoft.com/en-us/exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-emergency-mitigation-service ; https://nvd.nist.gov/vuln/detail/CVE-2026-42897

Remediation deadline: May 29, 2026

Description

Microsoft Exchange Server contains a cross-site scripting vulnerability during web page generation in Outlook Web Access and when certain interaction conditions are met, arbitrary JavaScript can be executed in the browser context.

Timeline

Published:May 15th, 2026 12:00 AM

Last modified:May 15th, 2026 12:00 AM

Added to KEV:May 15th, 2026

CVSS Scoring

No CVSS v3 score available

Affected Software

From NVD CPE configuration data

Vendors

Microsoft

Products

Microsoft

Weaknesses (CWE)

CWE-79

References & Reports

Advisories, patches, and third-party reports

No references available.

Source: CISA KEV + NVD · Data may lag official sources by up to one minute