Local privilege escalation via LSA TOCTOU race
Published Apr 8, 2025 · Updated Aug 10, 2026
Time-of-check time-of-use race in Microsoft Windows LSA allows local users to gain elevated privileges on affected builds. Microsoft identifies LSA as the locus but has not disclosed which checked object changes before use or which operation consumes it. Exploitation requires prior local authorization and winning a high-complexity race, with the consequence limited to elevated privileges on the same system.
Summary
What happened
Time-of-check time-of-use race in Microsoft Windows LSA allows local users to gain elevated privileges on affected builds. Microsoft identifies LSA as the locus but has not disclosed which checked object changes before use or which operation consumes it. Exploitation requires prior local authorization and winning a high-complexity race, with the consequence limited to elevated privileges on the same system.
The record
- CVE
- CVE-2025-21191
- Published
- Apr 8, 2025
- Updated
- Aug 10, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- CWE-367, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 8, 2025CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=10.0.10240.0 <10.0.10240.20978
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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