Cyber Resilience

CVE-2026-27929

Race Condition in Microsoft Windows 10 21H2 ≤ 10.0.19044.7184

Race Condition
Published
14 April 2026
Modified
22 April 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0019 8th percentile
Risk Priority 49 floored blend · peak EPSS

Summary

CVE-2026-27929 is a high-severity Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 7.0 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-25 (Reference Monitor) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Time-of-check time-of-use (toctou) race condition in Windows LUAFV allows an authorized attacker to elevate privileges locally.

CWE(s)
CWE-367

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
attack.mitre.org →
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
attack.mitre.org →
T1574 Hijack Execution Flow Stealth
Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20816Same product: Microsoft Windows 10 1607
CVE-2026-20831Same product: Microsoft Windows 10 1607
CVE-2025-48001Same product: Microsoft Windows 10 1607
CVE-2025-29833Same product: Microsoft Windows 10 1607
CVE-2026-21240Same product: Microsoft Windows 10 1809
CVE-2025-21191Same product: Microsoft Windows 10 1607
CVE-2024-49046Same product: Microsoft Windows 10 1607
CVE-2025-54093Same product: Microsoft Windows 10 1607
CVE-2025-50158Same product: Microsoft Windows 10 1607
CVE-2025-29969Same product: Microsoft Windows 10 1607

Affected Assets

microsoft
windows 10 1607
≤ 10.0.14393.9060 · ≤ 10.0.14393.9060
microsoft
windows 10 1809
≤ 10.0.17763.8644 · ≤ 10.0.17763.8644
microsoft
windows 10 21h2
≤ 10.0.19044.7184 · ≤ 10.0.19044.7184 · ≤ 10.0.19044.7184
microsoft
windows 10 22h2
≤ 10.0.19045.7184 · ≤ 10.0.19045.7184 · ≤ 10.0.19045.7184
microsoft
windows 11 23h2
≤ 10.0.22631.6936 · ≤ 10.0.22631.6936
microsoft
windows 11 24h2
≤ 10.0.26100.8246 · ≤ 10.0.26100.8246
microsoft
windows 11 25h2
≤ 10.0.26200.8246 · ≤ 10.0.26200.8246
microsoft
windows 11 26h1
≤ 10.0.28000.1836 · ≤ 10.0.28000.1836
microsoft
windows server 2012
all versions, r2
microsoft
windows server 2016
≤ 10.0.14393.9060
+4 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V15.4.2
  • V17.2.6

Mitigating Controls (NIST 800-53 r5) AI

AC-25 Reference Monitor good match

A reference monitor that is always invoked and analyzable structurally eliminates the non-atomic check-then-use pattern underlying TOCTOU.

AC-3 Access Enforcement partial match

Access enforcement that performs an atomic check-and-use decision directly stops the window in which a TOCTOU race can be exploited.

SC-39 Process Isolation partial match

Process isolation limits the blast radius of a successful TOCTOU exploitation but does not remove the race itself.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards and reviews that prevent TOCTOU race conditions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.17 Clock synchronization none match
none

Reliable, synchronized time across systems narrows the exploitable window in which a resource state can change between a security check and its use.

References