CRITICALVulnerability
Verified
Global

NVD CRITICAL: CVE-2026-56191 — Improper authentication in Microsoft Exchange Online allows an unauthorized atta...

·Source: NIST NVD

Updated:

Executive Summary

Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network.

Analysis

Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network. CVSS Score: 10. Published: 2026-07-24T01:17:36.417.

Indicators of Compromise (1)

CVE (1)
CVE-2026-56191
NVDMITRE CVE
Source Attribution

Originally published by NIST NVD on Jul 24, 2026. Verified by: NIST.

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