Patch tracker / CVE reference / CVE-2026-34350

CVE-2026-34350

CVE-2026-34350 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 6.5 (Medium). Microsoft has shipped the fix: deploy one of the 2 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

Medium
6.5
CVSS v3
2.2%
EPSS, 30 days
Medium
Severity

Not in the CISA KEV catalog. EPSS exploit probability 2.2%. CVSS 6.5 (Medium).

This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2026-34350

This is a Storport miniport driver flaw in Windows Server 2025, including Server Core, that Microsoft rates Critical at CVSS 9.8 despite being classified as a Denial of Service issue. The Storport driver sits in the storage I/O path, so exposure hits any Server 2025 host handling disk or storage controller traffic. It is not in CISA KEV and has no known ransomware use, but the 80 percent EPSS score signals that working exploitation is likely in the near term.

Do this: Prioritize the current Microsoft patch for CVE-2026-34350 on all Windows Server 2025 hosts including Server Core installations, starting with storage and database servers.

AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-34350

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

Schedule normally
No exploitation observed as of 2026-10-14: not in the CISA KEV catalog, EPSS 2%.
Fixed by KB5087423 and 1 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.
Do this now: Deploy with your normal update cycle. This page refreshes daily; the verdict changes the day the data does.

Official patch(es) for CVE-2026-34350

Lower priority: patch in your normal cycle. In Intune or Defender, confirm whether the fixing updates KB5087423, KB5087539 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security updates below to fix CVE-2026-34350. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.

KB5087423KB5087539

Scope and sources

Affected products
Fixed by the same updates
CVE-2025-54518CVE-2026-41089CVE-2026-41096CVE-2026-34329CVE-2026-40403CVE-2026-40415CVE-2026-34332CVE-2026-33834
Authoritative references
Official CVE record (cve.org)NVD detailMicrosoft MSRCFIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
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