9.9Critical
Microsoft Fabric
CVE-2026-63509
Relative path traversal in Microsoft Fabric allows an authorized attacker to elevate privileges over a network.
What this means for your business
- It affects Microsoft Fabric. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.6% chance of attack attempts being seen in the next 30 days, ranking above 48% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Microsoft Fabric, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Fastnexa security experts
Not sure if your company is exposed to CVE-2026-63509?
Tell us where you run Microsoft Fabric and a Fastnexa penetration tester will check whether this flaw, or others like it, can be used against your websites, apps and network.
The full test is free for our first 10 founding clients until 31 December 2026. See the offer
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Scoring
- CVSS
- 9.9 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H- Weakness
- CWE-23
- Assigned by
- secure@microsoft.com
Dates
- Published
- 2026-08-20
- Last modified
- 2026-09-04
- Sources
- NVD
Affected products
- Microsoft Fabricall versions
As listed in the NVD configuration data. Not a statement about your estate.