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CVE-2026-70075 Microsoft CVE debrief

A time-of-check time-of-use (toctou) race condition in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to bypass a security feature locally. Multiple Windows versions are affected, including Windows 10, Windows 11, and Windows Server. This vulnerability has a medium severity and defenders should assess exposure and prioritize patching. The affected products include Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2019, Windows Server 2019 (Server Core The CVE-

Vendor
Microsoft
Product
Windows 10 Version 1809
CVSS
MEDIUM 4.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-13
Original CVE updated
2026-10-14
Advisory published
2026-10-13
Advisory updated
2026-10-14

Who should care

Defenders responsible for Windows systems, particularly those using Virtualization-Based Security (VBS) Enclave, should assess exposure and prioritize patching.

Why it matters

CVE-2026-70075 is a medium-severity vulnerability in Windows Virtualization-Based Security (VBS) Enclave that allows authorized attackers to bypass a security feature locally. Defenders should prioritize patching and verifying the security feature configuration to prevent potential local attacks. The vulnerability affects multiple Windows versions, and evidence of exploitation is limited.

  • Local security feature bypass by authorized attackers
  • Potential for lateral movement and escalation
  • Need for patching and configuration verification
  • Limited evidence of exploitation or impact

Technical summary

A time-of-check time-of-use (toctou) race condition in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to bypass a security feature locally. The vulnerability affects multiple Windows versions, including Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows Server 2025, and Windows Server 2025 (Server Core installation).

Defensive priority

Defenders should prioritize patching and verifying the security feature bypass vulnerability in Windows Virtualization-Based Security (VBS) Enclave.

Recommended defensive actions

  • Patch affected Windows versions
  • Verify VBS Enclave security feature configuration
  • Monitor for local authorized attacker activity

Evidence notes

The CVE Program and NVD provide official records of the vulnerability. Microsoft provides a vendor advisory with patch information. The vulnerability affects multiple Windows versions, including Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2019, Windows Server 2019 (Server Core installation),

Sources and references

Verified primary and authoritative sources

  • CVE-2026-70075 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-70075

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-70075 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-70075

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.