CVE-2025-53786: U.S. CISA Issues Emergency Directive for Post-Authentication Vulnerability in Microsoft Exchange Hybrid Configurations
On August 6, 2025, Microsoft disclosed a high-severity post-authentication vulnerability affecting on-premises Microsoft Exchange servers configured for hybrid-joined environments, tracked as CVE-2025-53786. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has issued Emergency Directive 25-02, requiring federal agencies to patch the vulnerability by Monday, August 11.