VulnerabilityAnalyzed
CVE-2026-84009
Time-of-check time-of-use (toctou) race condition in Windows Projected File System allows an authorized attacker to perform tampering locally.
MEDIUM 4.7EPSS 0.20%
Does this matter?
Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own.
Description
Time-of-check time-of-use (toctou) race condition in Windows Projected File System allows an authorized attacker to perform tampering locally.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.20% probability · 9th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · microsoft/windows 11 25h2 · microsoft/windows 11 26h1 · microsoft/windows 11 26h2 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2025
- Source
- secure@microsoft.com
EPSS moved from 0.2% on 14 October 2026 to 0.2% on 26 October 2026.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-84009Vendor Advisory, Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.