CVE-2026-56191 — Microsoft Exchange Online Tampering Vulnerability

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

Published: 2026-07-24 · CVSS: 10.0 · CVSS 3.1

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

Original CVE JSON · STIX 2.1

Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7