Microsoft has disclosed a new security vulnerability impacting on-premise versions of Exchange Server that it said has come under active exploitation in the wild.
The vulnerability, tracked as CVE-2026-42897 (CVSS score: 8.1), has been described as a spoofing bug stemming from a cross-site scripting flaw. An anonymous researcher has been credited with discovering and reporting the issue.
” Microsoft has disclosed a new security vulnerability impacting on-premise versions of Exchange Server that it said has come under active exploitation in the wild.
The vulnerability, tracked as CVE-2026-42897 (CVSS score: 8.1), has been described as a spoofing bug stemming from a cross-site scripting flaw. An anonymous researcher has been credited with discovering and reporting the issue.
” The Hacker News
