CVE-2025-6338
Possible denial of service with multiple incoming connections to a Schannel based server with a TLS backend
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.
INFO
Published Date :
Oct. 16, 2025, 10:15 a.m.
Last Modified :
Oct. 16, 2025, 10:15 a.m.
Remotely Exploit :
Yes !
Source :
a59d8014-47c4-4630-ab43-e1b13cbe58e3
Affected Products
The following products are affected by CVE-2025-6338
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | a59d8014-47c4-4630-ab43-e1b13cbe58e3 | ||||
| CVSS 4.0 | CRITICAL | a59d8014-47c4-4630-ab43-e1b13cbe58e3 |
Solution
- Update Qt to version 6.9.2 or later.
- Update Qt to a version later than 6.8.3.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-6338.
| URL | Resource |
|---|---|
| https://codereview.qt-project.org/c/qt/qtbase/+/651495 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-6338 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-6338
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-6338 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-6338 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by a59d8014-47c4-4630-ab43-e1b13cbe58e3
Oct. 16, 2025
Action Type Old Value New Value 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-459 Added Reference https://codereview.qt-project.org/c/qt/qtbase/+/651495