CVE-2025-6338

Possible denial of service with multiple incoming connections to a Schannel based server with a TLS backend

Published Oct 16, 2025 CVSS 4.0 · 9.2 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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. 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.
CPEs cpe:2.3:a:qt:qt:*:*:windows:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Microsoft
Microsoft windows
Qt
Qt qt
Vendors & Products Microsoft
Microsoft windows
Qt
Qt qt
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Possible denial of service with multiple incoming connections to a Schannel based server with a TLS backend
Weaknesses CWE-459
References
Metrics cvssV4_0

{'score': 9.2, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
TQtC
Published
Updated
Jul 29, 2026, 8:54 AM
Reserved
Jun 19, 2025, 10:25 AM
Status
Deferred
Published
Oct 16, 2025, 10:15 AM
Modified
Oct 9, 2026, 10:10 AM