CVE-2026-65678: Windows Win32k Elevation of Privilege Vulnerability

highCVSS 7CVE-2026-65678

Use after free in Windows Win32K allows an authorized attacker to elevate privileges locally.

CSIRTS triage

vendor: Microsoft product: Windows Win32k Privilege escalation Memory corruption

What: Use-after-free in Windows Win32K allows privilege elevation.
Who is affected: Authorized attackers with local access to affected Windows systems.
Urgency: High severity (CVSS 7.0) with no public exploitation; prioritize remediation.
Action: Apply the latest Windows security update addressing CVE-2026-65678.

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
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65678

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-2026-656780.21% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 12% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-65678	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Windows Win32k Elevation

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-65776: Use after free in Windows Win32K allows an authorized attacker to elevate privileges locally.nvd · 2026-08-11
highCVE-2026-65775: Use after free in Windows Win32K allows an authorized attacker to elevate privileges locally.nvd · 2026-08-11
highCVE-2026-65678: Use after free in Windows Win32K allows an authorized attacker to elevate privileges locally.nvd · 2026-08-11
highCVE-2026-62885: Heap-based buffer overflow in Windows Win32K allows an authorized attacker to elevate privileg…nvd · 2026-08-11
highCVE-2026-62877: Stack-based buffer overflow in Windows Win32K allows an authorized attacker to elevate privile…nvd · 2026-08-11
highCVE-2026-62876: Out-of-bounds read in Windows Win32K allows an authorized attacker to elevate privileges local…nvd · 2026-08-11