May 15, 2026 · Applied Cybernetics Group
CVE-2026-42897 — Microsoft Microsoft
Microsoft Exchange Server Cross-Site Scripting Vulnerability
- Added to KEV
2026-05-15- Federal due date
2026-05-29- Vendor
- Microsoft
- Product
- Microsoft
- EPSS
- 92.2th percentile (score 0.079, as of
2026-06-08) - NVD CVSS v3.1
- 8.1 (HIGH)
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2026-42897
CISA short 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.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
NVD 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.