What is CVE-2026-45487?

CVE-2026-45487 is a high-severity vulnerability in Microsoft Windows_10_21h2, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.8/10. Published 2026-06-09.

How severe is CVE-2026-45487?

High severity. CVSS v3 base score is 7.8 out of 10.

Vulnerability in Microsoft Windows_10_21h2

CVE-2026-45487

Time-of-check time-of-use (TOCTOU) race condition in Program Compatibility Assistant Service allows an authorized attacker to elevate privileges locally.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

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_server_2022
Microsoft Windows_server_2025

Weakness classification (CWE)

CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

secure@microsoft.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-45487?: CVE-2026-45487 is a high-severity vulnerability in Microsoft Windows_10_21h2, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.8/10. Published 2026-06-09.
How severe is CVE-2026-45487?: High severity. CVSS v3 base score is 7.8 out of 10.