CVE-2026-62771

Analyzed Analyzed - Analysis Complete

Heap Overflow in Windows Cloud Files Mini Filter Driver

Publication date: 2026-08-11

Last updated on: 2026-08-16

Assigner: Microsoft Corporation

Description

Heap-based buffer overflow in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-11

Last Modified

2026-08-16

Generated

2026-09-01

AI Q&A

2026-08-11

EPSS Evaluated

2026-08-30

NVD

CVE-2026-62771

EUVD

EUVD-2026-56655

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_10_1809	to 10.0.17763.9115 (exc)
microsoft	windows_10_1809	to 10.0.17763.9115 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_server_2019	to 10.0.17763.9115 (exc)
microsoft	windows_server_2022	to 10.0.20348.5440 (exc)
microsoft	windows_server_2025	to 10.0.26100.33222 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This is a heap-based buffer overflow vulnerability in the Windows Cloud Files Mini Filter Driver. It allows an authorized attacker with local access to elevate their privileges on the system by exploiting the overflow.

Detection Guidance

This vulnerability is specific to the Windows Cloud Files Mini Filter Driver and requires local access to exploit. Detection typically involves monitoring for unusual privilege escalation events or crashes in the driver. Check Windows Event Viewer for application or system crashes related to the Cloud Files Mini Filter Driver (cldflt.sys). Use commands like 'sc query cldflt' to verify if the driver is running and 'driverquery /si' to list installed drivers for suspicious entries.

Impact Analysis

An attacker could exploit this to gain higher-level permissions on your system, potentially allowing them to install programs, view or delete data, or create new accounts with full user rights.

Compliance Impact

This vulnerability allows local privilege escalation via a heap-based buffer overflow in the Windows Cloud Files Mini Filter Driver. Such unauthorized access could potentially lead to data breaches or unauthorized modifications, which may impact compliance with standards like GDPR or HIPAA by compromising data confidentiality and integrity.

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the Windows Cloud Files Mini Filter Driver vulnerability.

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