Rollup 18 for Microsoft Exchange Server 2010 SP3 and previous versions has an SSRF vulnerability via the username parameter in /owa/auth/logon.aspx in the OWA (Outlook Web Access) login page.
Severity
CVSS 3.0
8.6 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
EPSS
11% chance of exploitation in the next 30 days; higher than 95% of CVEs (scores of 2026-10-31)