Will a zero-day vulnerability in Microsoft Exchange be exploited in the wild before being patched in 2026?

Microsoft Exchange has been a perennial target — ProxyLogon (2021), ProxyShell (2021), and OWASSRF (2022) were all exploited before widespread patching. Nation-state actors, particularly Chinese APTs, maintain persistent interest in Exchange infrastructure. This market forecasts whether Exchange will see another zero-day exploitation event in 2026.

Resolution Criteria

Resolves YES if: A CVE in Microsoft Exchange Server or Exchange Online is confirmed exploited in the wild before or on the same day as Microsoft's official patch release, per Microsoft's own Security Response Center or CISA KEV before 2026-11-01.