CVE-2026-63509 Microsoft Fabric Elevation of Privilege Vulnerability

Critical 9.9 Published 20 Aug 2026 Updated 28 Oct 2026

An authorized attacker can exploit relative path traversal in Microsoft Fabric to elevate privileges over the network.

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-2026-63509?

CVE-2026-63509 is a critical path traversal vulnerability in Microsoft Fabric, published on 20 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Relative path traversal in Microsoft Fabric allows an authorized attacker to elevate privileges over a network.

Weakness: CWE-23

Which versions are affected by CVE-2026-63509?

It affects 1 product.

Products include Microsoft Fabric.

How do I fix CVE-2026-63509?

No fix has been published for CVE-2026-63509 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-63509 being exploited?

There is no known exploitation of CVE-2026-63509 in the wild and no public exploit code.

Sources

Also known as GHSA-3r75-wcfw-gxm8.