Description
Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.
Affected products
microsoft: windows 11 26h1
References1
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72971 Vendor AdvisoryPatch
Metrics
- CVSS 3.1
-
5.5
MEDIUM
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - EPSS — exploit probability
- 0% percentile: 31 · as of 12 November 2026
- CWE
- CWE-59
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.