CVE-2023-35378

SYSTEM privilege escalation via undisclosed TOCTOU race

Published Aug 8, 2023 · Updated Aug 10, 2026

TOCTOU race condition in Microsoft Windows Projected File System allows local users to gain SYSTEM privileges. Microsoft identifies a time-of-check time-of-use race but has not disclosed the affected function, resource, or mismatched check and use. An authenticated low-privilege user must win the race locally; successful exploitation grants SYSTEM privileges on affected Windows 10, Windows 11, and Windows Server builds.

CVSS severity7.0
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

TOCTOU race condition in Microsoft Windows Projected File System allows local users to gain SYSTEM privileges. Microsoft identifies a time-of-check time-of-use race but has not disclosed the affected function, resource, or mismatched check and use. An authenticated low-privilege user must win the race locally; successful exploitation grants SYSTEM privileges on affected Windows 10, Windows 11, and Windows Server builds.

The record

CVE
CVE-2023-35378
Published
Aug 8, 2023
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-367, CWE-362, CAPEC-29, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.17763.0 <10.0.17763.4737

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.4737
Microsoft · Windows 11 version 21H2version=10.0.22000.0 <10.0.22000.2295
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.3324
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.3324
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.4737
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.2134
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.1906
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.4737; version=10.0.17763.0 <10.0.17763.4737

Published CVSS scores

7.0Microsoft CorporationCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CAPEC-29Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo