CVE-2026-42897
Medium 6.1 Exploited in the wild (KEV)
Confirmed active exploitation — CISA KEV catalog
- Name
- Microsoft Exchange Server Cross-Site Scripting Vulnerability
- Added to catalog
- Remediation due date (US federal)
- 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.
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 (MEDIUM)
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 71% (percentile: 99) as of 1 November 2026
- CWE
- CWE-79
Affected products
microsoft: exchange server; microsoft: exchange server subscription edition
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42897 MitigationVendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026… US Government Resource