exchange security

The U.S. National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA) and partner agencies released a compact, operational playbook on Oct. 30 that tells administrators to treat on‑premises Microsoft Exchange servers as “under imminent threat,” urging immediate...

Treat this as a fire alarm: four national security agencies have issued coordinated, high‑urgency guidance telling organizations that on‑premises and hybrid Microsoft Exchange Server environments are being actively targeted and must be hardened immediately — and that a separate, critical Windows...

The U.S. National Security Agency has joined CISA in sounding the alarm: on-premises and hybrid Microsoft Exchange Server deployments remain “at high risk of compromise,” and the federal guidance released this fall consolidates a short, urgent hardening checklist administrators must run through...

CISA has published an urgent, practical playbook titled Microsoft Exchange Server Security Best Practices that tells organizations to harden on‑premises Exchange, adopt Microsoft’s hybrid hardening guidance, and decommission any remaining end‑of‑life (EOL) on‑premises or hybrid Exchange servers...

Germany’s national cybersecurity agency has warned that an overwhelming majority of the country’s publicly reachable Exchange servers remain on unsupported software just after Microsoft ended mainstream updates for Exchange Server 2016 and 2019 — a finding that raises immediate operational...

Security researcher Dirk‑jan Mollema’s discovery of two linked vulnerabilities in Microsoft’s Entra ID architecture exposed a failure mode that, by design, could have allowed an attacker with limited on‑premises access to gain near‑complete control over hybrid Microsoft environments — a chain...

A newly disclosed security flaw in Microsoft Exchange hybrid deployments is triggering urgent action among IT administrators worldwide, as Microsoft warns of a critical vulnerability—CVE-2025-53786—that exposes hybrid environments to stealthy privilege escalation attacks. As organizations...

A new high-severity security vulnerability is causing alarm among businesses that utilize hybrid Microsoft Exchange deployments, as both Microsoft and the US Cybersecurity and Infrastructure Security Agency (CISA) issue urgent advisories. This flaw—affecting Exchange Server 2016, 2019, and the...

A critical security vulnerability, identified as CVE-2025-53786, has been discovered in hybrid deployments of Microsoft Exchange Server. This flaw allows attackers with local administrative access to escalate their privileges within connected cloud environments, posing significant risks to...