Microsoft Exchange Server Cross-Site Scripting Vulnerability
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.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Turn on Microsoft alerts
Details
- Vendor
- Microsoft
- Product
- Exchange Server
- CVE
- CVE-2026-42897
- Affected versions
- Microsoft Exchange Server 2016 Cumulative Update 23 15.01: from 15.01.0.0 to 15.01.2507.069 (excluded) — fixed in 15.01.2507.069
Microsoft Exchange Server 2019 Cumulative Update 14 15.02: from 15.02.0.0 to 15.02.1544.041 (excluded) — fixed in 15.02.1544.041
Microsoft Exchange Server 2019 Cumulative Update 15 15.02: from 15.02.0.0 to 15.02.1748.046 (excluded) — fixed in 15.02.1748.046
Microsoft Exchange Server Subscription Edition RTM 15.02: from 15.02.0.0 to 15.02.2562.043 (excluded) — fixed in 15.02.2562.043 (from the advisory and NVD; check the exact builds in the official advisory) - CVSS score
- 8.1
- Actively exploited
- Yes, listed in the CISA Known Exploited Vulnerabilities catalog
- CISA due date
- May 29, 2026 (deadline for US federal agencies: a good benchmark for you too)
- Source
- CISA KEV – original advisory
- Published
- May 15, 2026
The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.