dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-33098

HIGH · 7.8 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 10.0.14393.9060 / 10.0.17763.8644 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Use after free in Windows Container Isolation FS Filter Driver allows an authorized attacker to elevate privileges locally.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A Use-After-Free vulnerability exists in the Windows Container Isolation FS Filter Driver. This memory corruption flaw allows a locally authenticated attacker to execute code with elevated privileges by exploiting improper memory handling in the container isolation layer.

MitigationApply Microsoft security patches for this vulnerability once available. Prioritize patching Windows systems running container workloads. Verify container isolation functionality after patching.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Windows 10 1607Operating system
Affected:< 10.0.14393.9060
Windows 10 1809Operating system
Affected:< 10.0.17763.8644
Windows 10 21h2Operating system
Affected:< 10.0.19044.7184
Windows 10 22h2Operating system
Affected:< 10.0.19045.7184
Windows 11 23h2Operating system
Affected:< 10.0.22631.6936
Windows 11 24h2Operating system
Affected:< 10.0.26100.8246
Windows 11 25h2Operating system
Affected:< 10.0.26200.8246
Windows 11 26h1Operating system
Affected:< 10.0.28000.1836

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows version and build number
    Run 'winver' or 'systeminfo | findstr "Build"' and note the full version and build number (e.g., 10.0.19045.xxxx)
    Affected if The build number is lower than the patch threshold for your Windows release: 14393.9060 for Windows 10 1607, 17763.8644 for Windows 10 1809, 19044.7184/19045.7184 for Windows 10 21h2/22h2, 22631.6936 for Windows 11 23h2, 26100.8246 for Windows 11 24h2, 26200.8246 for Windows 11 25h2, or 28000.1836 f
  2. Verify Container Isolation FS Filter Driver presence
    Run 'fltmc filters' from an elevated command prompt to list loaded filter drivers, or check for wcifs.sys in C:\Windows\System32\drivers\
    Affected if The 'wcifs' (Windows Container Isolation FS Filter) driver appears in the filter list or wcifs.sys exists on the system (vulnerability only applies when this driver is present)
  3. Confirm driver loaded status
    Run 'sc query wcifs' or check the driver load status via 'fltmc' output
    Affected if The wcifs driver service shows as RUNNING (vulnerability requires the driver to be actively loaded in kernel mode)

You are affected if your Windows build is below the threshold for your version AND the Container Isolation FS Filter Driver (wcifs) is loaded on your system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.14393.9060 / 10.0.17763.8644 / 10.0.19044.7184 or later
Fixed in 10.0.14393.906010.0.17763.864410.0.19044.7184
Interim mitigation

Apply Microsoft security patches for this vulnerability once available. Prioritize patching Windows systems running container workloads. Verify container isolation functionality after patching.

Recommended fix High confidence

Upgrade to the specified build number for your Windows version (e.g., Windows 10 22h2: 10.0.19045.7184 or later, Windows 11 23h2: 10.0.22631.6936 or later)

  1. Identify the current Windows build version by running 'winver' or 'systeminfo' from command prompt
  2. Determine which Windows version and build you are running from the affected list
  3. Apply the latest Microsoft Windows Security Update that includes the fix for CVE-2026-33098
  4. For Windows 10 1607: Upgrade to build 10.0.14393.9060 or later
  5. For Windows 10 1809: Upgrade to build 10.0.17763.8644 or later
  6. For Windows 10 21h2: Upgrade to build 10.0.19044.7184 or later
  7. For Windows 10 22h2: Upgrade to build 10.0.19045.7184 or later
  8. For Windows 11 23h2: Upgrade to build 10.0.22631.6936 or later
Caveat Standard Windows update risks apply; ensure backups and test in non-production environments before deploying organization-wide

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1607 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33098 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data