Microsoft Exchange CVEs more widely exploited than thought US CISA issues emergency guidance as impact of four newly disclosed Microsoft Exchange vulnerabilities becomes clearer Share this item with your network: By Published: 04 Mar 2021 14:49 The US government’s Cybersecurity and Infrastructure Security Agency (CISA) has issued an emergency directive warning all government civilian departments and agencies running an on-premise Microsoft Exchange installation to update or disconnect the product as the impact of four newly disclosed vulnerabilities – CVE-2021-26855, CVE-2021-26857, ...