Microsoft Exchange 'Under Imminent Threat', Act Now

Microsoft Exchange remains a prime target, with warnings that Exchange environments are “under imminent threat” and organisations should act now to mitigate risk as support for older servers ends. The piece notes that end-of-life servers will not receive essential updates or vulnerability patches, increasing exposure for enterprises.

It cites the August emergency directive from CISA that federal agencies mitigate a post-authentication vulnerability tracked as CVE-2025-53786, describing the flaw as posing a grave risk to organisations using Exchange hybrid-joined configurations. According to Cybersecurity and Infrastructure Security Agency (CISA), organisations are advised to avoid internet-exposing on-premises Exchange and to migrate to more secure options such as hosted or cloud-based mail services where possible.

The article also discusses the broader shift away from on-premises Exchange, emphasising the need for timely patch management and lifecycle governance to prevent business interruption and data loss. It was written by Arielle Waldman and published on 12 November 2025.