CVE-2026-48582 Microsoft Exchange Online Elevation of Privilege Vulnerability

Critical 9.6 Published 19 Jun 2026 Updated 24 Sep 2026

An authorized attacker can elevate privileges in Microsoft Exchange Online due to missing authorization checks.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-48582?

CVE-2026-48582 is a critical missing authorization vulnerability in Microsoft Exchange Online, published on 19 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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

Weakness: CWE-862

Which versions are affected by CVE-2026-48582?

It affects 1 product.

Products include Microsoft Exchange Online.

How do I fix CVE-2026-48582?

No fix has been published for CVE-2026-48582 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-48582 being exploited?

There is no known exploitation of CVE-2026-48582 in the wild and no public exploit code.

Sources

Also known as GHSA-j97v-rpjv-q4wf.