CVE-2026-45487: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows 10 Version 21H2
Time-of-check time-of-use (TOCTOU) race condition in Program Compatibility Assistant Service allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability is a TOCTOU race condition in the Program Compatibility Assistant Service of Windows 10 Version 21H2 (build 10.0.19044.0). It enables an authorized local attacker to elevate privileges by exploiting the timing window between checking and using a resource. The CVSS 3.1 base score is 7.8, indicating high severity with impacts on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
An authorized local attacker can exploit this race condition to elevate privileges, potentially gaining higher system rights than intended. This can lead to full system compromise affecting confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45487 to remediate this vulnerability.
CVE-2026-45487: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows 10 Version 21H2
Description
Time-of-check time-of-use (TOCTOU) race condition in Program Compatibility Assistant Service allows an authorized attacker to elevate privileges locally.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability is a TOCTOU race condition in the Program Compatibility Assistant Service of Windows 10 Version 21H2 (build 10.0.19044.0). It enables an authorized local attacker to elevate privileges by exploiting the timing window between checking and using a resource. The CVSS 3.1 base score is 7.8, indicating high severity with impacts on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
An authorized local attacker can exploit this race condition to elevate privileges, potentially gaining higher system rights than intended. This can lead to full system compromise affecting confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45487 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-05-12T16:07:22.617Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45487","vendor":"Microsoft"}]
Threat ID: 6a284cdf8dd33fbd85664d97
Added to database: 06/09/2026, 17:26:55 UTC
Last enriched: 07/29/2026, 21:57:30 UTC
Last updated: 07/31/2026, 20:42:23 UTC
Views: 62
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