CVE-2026-62811

Analyzed Analyzed - Analysis Complete

Heap-based Buffer Overflow in Windows HTTP.sys

Publication date: 2026-08-11

Last updated on: 2026-08-13

Assigner: Microsoft Corporation

Description

Heap-based buffer overflow in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-08-11

Last Modified

2026-08-13

Generated

2026-08-31

AI Q&A

2026-08-11

EPSS Evaluated

2026-08-30

NVD

CVE-2026-62811

EUVD

EUVD-2026-56673

Affected Vendors & Products

Vendor	Product	Version / Range
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_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 Windows HTTP.sys. An authorized attacker can exploit it to elevate their privileges locally on an affected system.

Detection Guidance

This vulnerability is specific to Windows HTTP.sys and requires local access to exploit. Detection typically involves monitoring for unusual system behavior or applying Microsoft's security updates. No direct detection commands are provided in the available resources.

Impact Analysis

An attacker with local access could exploit this to gain higher privileges, potentially allowing them to execute arbitrary code, install programs, or access sensitive data on your system.

Compliance Impact

This vulnerability allows local privilege escalation via a heap-based buffer overflow in Windows HTTP.sys. Such unauthorized privilege elevation could lead to unauthorized access to sensitive data, which may violate compliance requirements under GDPR (data protection) and HIPAA (health information privacy).

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the heap-based buffer overflow in HTTP.sys. Monitor Microsoft's update guide for patches and install them promptly.

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