CVE-2026-42897: Microsoft Exchange Server Cross-Site Scripting Vulnerability
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.
Other sources
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.
— CISA
Microsoft Exchange Server Spoofing Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.01.2507.069Patch KB5094144 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.02.1544.041Patch KB5094142 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.02.1748.046Patch KB5094140 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.02.2562.043Patch KB5094139
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42897?
CVE-2026-42897 has a critical severity rating due to its potential for spoofing attacks in Microsoft Exchange Server.
How do I fix CVE-2026-42897?
To fix CVE-2026-42897, apply the latest security updates provided by Microsoft for affected versions of Exchange Server.
What versions of Microsoft Exchange Server are affected by CVE-2026-42897?
CVE-2026-42897 affects Microsoft Exchange Server 2019, 2016, and the Subscription Edition RTM.
What type of vulnerability is CVE-2026-42897?
CVE-2026-42897 is classified as a cross-site scripting (XSS) vulnerability allowing for spoofing attacks.
Can CVE-2026-42897 be exploited remotely?
Yes, CVE-2026-42897 can be exploited remotely if the attacker sends malicious input to the affected Microsoft Exchange Server.