CVE Catalog
CVE-2026-56191
CriticalCVSS 10.0Exploitation Probability (EPSS)
Low risk0.68%
49th percentile - higher than 49% of all known CVEs
Summary
Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network.
Risk Assessment
An unauthorized attacker can modify data in Exchange Online, potentially leading to integrity breaches of email and other data.
Recommendation
Apply the security update provided by Microsoft for Microsoft Exchange Online.
Original NVD description (English source)
Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network.