CVE-2026-61939: Winlogon Elevation of Privilege Vulnerability

highCVSS 7CVE-2026-61939

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

CSIRTS triage

vendor: Microsoft product: Winlogon Privilege escalation

What: Use-after-free vulnerability enables local privilege escalation.
Who is affected: Authorized attackers on Windows systems running Winlogon.
Urgency: High severity (CVSS 7.0); privilege escalation in core authentication component is critical.
Action: Apply Microsoft security patch when available.

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-2026-61939

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-2026-619390.25% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 16% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-61939	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

critical[NEW] [critical] Microsoft Windows Products: Multiple vulnerabilitiescert-bund
unknownexploitedNCSC-2026-0284 [1.00] [M/H] Vulnerabilities patched in Microsoft Windowsncsc-nl
highCVE-2026-61939: Use after free in Winlogon allows an authorized attacker to elevate privileges locally.nvd

Recent advisories for Winlogon Elevation of

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-2026-61939: Use after free in Winlogon allows an authorized attacker to elevate privileges locally.nvd · 2026-08-11
highCVE-2026-42989: Winlogon Elevation of Privilege Vulnerabilitymsrc · 2026-06-09