CVE-2026-45487: Windows Program Compatibility Assistant Service Elevation of Privilege Vulnerability

highCVSS 7.8CVE-2026-45487

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

CSIRTS triage

vendor: Microsoft product: Windows Program Compatibility Assistant Privilege escalation

What: A time-of-check time-of-use (TOCTOU) race condition allows an authorized attacker to elevate privileges locally.
Who is affected: Authorized users of Windows with the Program Compatibility Assistant Service.
Urgency: Remediation is urgent due to the high severity and potential for privilege escalation.
Action: Apply the latest security patch for Windows.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.8
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45487

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-454870.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 8% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45487	coverage & exploitation status	NVD · CVE.org

CVE-2026-45487: Windows Program Compatibility Assistant Service Elevation of Privilege Vulnerability

CSIRTS triage

Details

Exploitation outlook

Referenced CVEs

More from Microsoft Security Response Center