CVE-2026-84009

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 24/100
Published: 2026-10-13 Modified: 2026-10-28 First seen: 2026-10-29 Status: active

Attack Surface

No Interaction Integ. Impact

CVSS Vector Breakdown

AV: Local
AC: High
PR: Low
UI: None
S: Unchanged
C: None
I: High
A: None

Description

Time-of-check time-of-use (toctou) race condition in Windows Projected File System allows an authorized attacker to perform tampering locally.

Affected Software (49)

VendorProductVersion
Microsoft Windows 10 Version 1809 10.0.17763.0 < 10.0.17763.9376
Microsoft Windows 10 Version 1809 10.0.17763.0 < 10.0.17763.9376
Microsoft Windows 10 Version 21H2 10.0.19044.0 < 10.0.19044.7807
Microsoft Windows 10 Version 21H2 10.0.19044.0 < 10.0.19044.7807
Microsoft Windows 10 Version 22H2 10.0.19045.0 < 10.0.19045.7807
Microsoft Windows 10 Version 22H2 10.0.19045.0 < 10.0.19045.7807
Microsoft Windows 11 Version 23H2 10.0.22631.0 < 10.0.22631.7652
Microsoft Windows 11 Version 23H2 10.0.22631.0 < 10.0.22631.7652
Microsoft Windows 11 Version 24H2 10.0.26100.0 < 10.0.26100.9711
Microsoft Windows 11 Version 24H2 10.0.26100.0 < 10.0.26100.9711
Microsoft Windows 11 Version 25H2 10.0.26200.0 < 10.0.26200.9711
Microsoft Windows 11 Version 25H2 10.0.26200.0 < 10.0.26200.9711
Microsoft Windows 11 Version 26H2 10.0.26300.0 < 10.0.26300.9711
Microsoft Windows 11 Version 26H2 10.0.26300.0 < 10.0.26300.9711
Microsoft Windows 11 version 23H2 10.0.22631.0 < 10.0.22631.7652
Microsoft Windows 11 version 23H2 10.0.22631.0 < 10.0.22631.7652
Microsoft Windows 11 version 26H1 10.0.28000.0 < 10.0.28000.3231
Microsoft Windows 11 version 26H1 10.0.28000.0 < 10.0.28000.3231
Microsoft Windows Server 2019 10.0.17763.0 < 10.0.17763.9376
Microsoft Windows Server 2019 10.0.17763.0 < 10.0.17763.9376
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.0 < 10.0.17763.9376
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.0 < 10.0.17763.9376
Microsoft Windows Server 2022 10.0.20348.0 < 10.0.20348.5761
Microsoft Windows Server 2022 10.0.20348.0 < 10.0.20348.5761
Microsoft Windows Server 2025 10.0.26100.0 < 10.0.26100.33650
Microsoft Windows Server 2025 10.0.26100.0 < 10.0.26100.33650
Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.0 < 10.0.26100.33650
Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.0 < 10.0.26100.33650
microsoft windows_10_1809 < 10.0.17763.9376
microsoft windows_10_1809 < 10.0.17763.9376
Showing 30 of 49 entries

References & Advisories (1)

Bug Bounty Relevance

24 / 100
✓ No user interaction

CVSS Score

4.7 / 10.0 v3.1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

EPSS — Exploitation Probability

0.20%
Raw Score 0.001970
Percentile 9.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00197
2026-10-28
0.00197

Intelligence Sources

mitre ref →