CVE-2026-54987: Windows Overlay Filter Elevation of Privilege Vulnerability

CSIRTS triage

What

A heap-based buffer overflow in Windows Overlay Filter allows an authorized attacker to elevate privileges locally.

Who is affected

Authorized users of Windows Overlay Filter are affected.

Urgency

Remediation is urgent due to the high severity and potential for local privilege escalation.

Action

Apply the latest security patch for Windows Overlay Filter.

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

Details

Source

Microsoft Security Response Center (INTL · vendor-psirt · site)

Severity

high — CVSS 7.8

Published

2026-07-14

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54987

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-2026-549870.24% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 15% of all scored CVEs.

Referenced CVEs

Same CVEs, other sources

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

• unknownexploitedNCSC-2026-0231 [1.00] [M/H] Vulnerabilities fixed in Microsoft Windowsncsc-nl
• highCVE-2026-54987: Heap-based buffer overflow in Windows Overlay Filter allows an authorized attacker to elevate …nvd