What is CVE-2026-48582?

CVE-2026-48582 is a critical-severity vulnerability in Microsoft Exchange Online, classified under Missing Authorization. CVSS score: 9.6/10. Published 2026-06-19.

How severe is CVE-2026-48582?

Critical severity. CVSS v3 base score is 9.6 out of 10.

Auth bypass in Microsoft Exchange Online

CVE-2026-48582

Missing authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N.

Affected products

Microsoft Exchange Online

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-48582?: CVE-2026-48582 is a critical-severity vulnerability in Microsoft Exchange Online, classified under Missing Authorization. CVSS score: 9.6/10. Published 2026-06-19.
How severe is CVE-2026-48582?: Critical severity. CVSS v3 base score is 9.6 out of 10.