Microsoft Patch Tuesday

This month's Microsoft Security Update Guide release: severity and exploitation dashboards, a searchable CVE browser, and a downloadable brief.

Browse This Release's CVEs

Severity
Exploitation

1 of 448 CVEs match the current filters, sorted by EVULNABLE Risk.

Filtered by Matching “CVE-2026-72971” — remove Clear all
CVEs in this Patch Tuesday release matching the current filters, ranked by EVULNABLE Risk Score
CVE TitleMSRC severity EVRS CVSS EPSS KEV Actively Exploited Product(s)
CVE-2026-72971 Windows Container Isolation FS Filter Driver (unionfs.sys) Tampering Vulnerability Important 24 Elevated 5.5 0.005 No No Windows 11 version 26H1 for x64-based Systems, Windows 11 Version 26H1 for ARM64-based Systems
Download filtered CVEs (CSV) Patch Tuesday Brief (PDF)

The CSV is exactly the 1 CVE(s) matching the filters above. The PDF is the full leadership brief — at-a-glance summary, Patch First spotlight, top affected products, and the complete per-CVE inventory — not filtered to what is shown here.

CVE detail

Expand any CVE for its description, EVRS score breakdown, and affected products.

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

Tampering

EVULNABLE Risk · priority 24/100 Elevated Intelligence coverage 90/100 — no ransomware association data, no CISA KEV listing date

Recommended priority: Scheduled Maintenance

Why this score: Publicly disclosed before a patch shipped, and CVSS base score 5.5.

Exploitation status: Publicly Disclosed

Microsoft Exploitability Index: Exploitation Unlikely

CVSS v3.1 base score: 5.5

FIRST EPSS: 0.005 (39.1st pctl) — probability of exploitation in the next 30 days, with its rank across all scored CVEs

CISA KEV: Not currently listed

KB article(s): 5121000

Affected product(s): Windows 11 version 26H1 for x64-based Systems, Windows 11 Version 26H1 for ARM64-based Systems

Microsoft Security Update Guide ↗ NVD ↗

Data sources & attribution

Known-exploitation status, required actions, ransomware association and remediation deadlines come from the CISA Known Exploited Vulnerabilities Catalog. Exploitation probability and percentile are provided by FIRST.org's EPSS, used under FIRST's open data terms.

Microsoft Patch Tuesday data is sourced from the Microsoft Security Update Guide; lifecycle milestones from endoflife.date. Linux distribution advisories come from Red Hat, Ubuntu and Debian; vendor bulletins from Adobe, Apple, Chrome, Cisco, Ivanti and Oracle, each linked to its own advisory.