CVE-2025-6338— Possible denial of service with multiple incoming connections to a Schannel based server with a TLS backend
Quick assessment
Affected
Qt Qt
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Qt是Qt开源的一个跨平台的应用程序开发框架。 Qt 5.15.0版本至6.8.3版本和6.9.0版本至6.9.2之前版本存在安全漏洞，该漏洞源于Qt Network的Schannel支持清理不完整，可能导致长期拒绝服务。
Possible ATT&CK Techniques 1 AI
T1499 · Endpoint Denial of Service
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I. Basic Information for CVE-2025-6338
Vulnerability Information
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Vulnerability Title
Possible denial of service with multiple incoming connections to a Schannel based server with a TLS backend
Source: CVE Program / CVE List V5
Vulnerability Description
There is an incomplete cleanup vulnerability in Qt Network's Schannel support on Windows which can lead to a Denial of Service over a long period.
This issue affects Qt from 5.15.0 through 6.8.3, from 6.9.0 before 6.9.2.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Source: CVE Program / CVE List V5
Vulnerability Type
清理环节不完整
Source: CVE Program / CVE List V5
Vulnerability Title
Qt 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Qt是Qt开源的一个跨平台的应用程序开发框架。 Qt 5.15.0版本至6.8.3版本和6.9.0版本至6.9.2之前版本存在安全漏洞，该漏洞源于Qt Network的Schannel支持清理不完整，可能导致长期拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2025-6338
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V. Comments for CVE-2025-6338
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