CSIRTS // UNIFIED SECURITY ADVISORY FEEDSYS ● ONLINE · POWERED BY INTELFUSIONS.COM

← Back to feed

CVE-2026-72971: Windows Container Isolation FS Filter Driver (unionfs.sys) Tampering Vulnerability

mediumCVSS 5.5CVE-2026-72971
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.

CSIRTS triage

vendor: Microsoftproduct: Windows Container Isolation FS Filter DriverPath traversalOther
What
Link following vulnerability in unionfs.sys allows an authorized attacker to perform tampering locally.
Who is affected
Windows Container environments with unpatched unionfs.sys are affected.
Urgency
Medium priority; local tampering vulnerability not currently exploited but affects authenticated users.
Action
Apply the latest Windows Container security update.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch Windows Container Isolation FS Filter Driver

Get an email when a new Windows Container Isolation FS Filter Driver advisory drops — max one per day, one-click unsubscribe.

Details

Source
Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity
medium — CVSS 5.5
Published
2026-08-11
Exploitation
Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72971

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2026-72971coverage & exploitation statusNVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

More from Microsoft Security Response Center