CVE-2026-63509: Microsoft Microsoft Fabric

Microsoft Fabric Elevation of Privilege Vulnerability

CVSS 9.9 CriticalCriticalEPSS 0.010 · 63rd percentile

Critical, because:

CVSS score 9.9: 9.0 or more.

Published by the CVE Program (CNA: microsoft) at 20 Aug 2026, 21:47 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Microsoft	Microsoft Fabric	affected -

Identifiers

CVE-2026-63509

CNA

microsoft

Weakness (CWE)

CWE-23

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Microsoft Fabric contains a relative path traversal vulnerability that lets an authorized attacker elevate privileges over a network. The source does not list affected versions or a fix, and it gives few other details. Because no fixed version is listed, check Microsoft's advisory for update guidance.

Written 12 Nov 2026.

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.9	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C	CNA (microsoft)

CISA KEV Not listed.
EPSS 0.010, the 63rd percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

20 Aug 2026, 21:47 UTC Confirmed by the CVE List

Sources

References from the CNA

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63509 vendor-advisorypatch

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.