CVE-2026-42897
Microsoft Exchange Server Spoofing Vulnerability
Microsoft Exchange Server Cross-Site Scripting Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
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.
CISA notes
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
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.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:CAffected Products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 23 | 15.01.0.0 to <15.01.2507.069 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 14 | 15.02.0.0 to <15.02.1544.041 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 15 | 15.02.0.0 to <15.02.1748.046 |
| Microsoft | Microsoft Exchange Server Subscription Edition RTM | 15.02.0.0 to <15.02.2562.043 |
References
1 LinksRecord Details
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Related Tool Categories
Tool categories that test for or protect against this vulnerability class.
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