high8.1Known exploited
CVE-2026-42897
Microsoft Exchange Server Cross-Site Scripting Vulnerability
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-05-15. Federal due date: 2026-05-29.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Impact
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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Exchange Server | Versions 2016, 2019 |
| Microsoft | Exchange Server Subscription Edition | before 15.02.2562.043 |