CVE-2026-23666
.NET Framework Denial of Service Vulnerability
Description
Improper input validation in .NET Framework allows an unauthorized attacker to deny service over a network.
INFO
Published Date :
April 14, 2026, 6:16 p.m.
Last Modified :
May 7, 2026, 7:46 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-23666
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.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | f38d906d-7342-40ea-92c1-6c4a2c6478c8 | ||||
| CVSS 3.1 | HIGH | [email protected] |
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-2026-23666.
| URL | Resource |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23666 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-23666 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-2026-23666
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-2026-23666 vulnerability anywhere in the article.
-
CrowdStrike.com
April 2026 Patch Tuesday: Two Zero-Days and Eight Critical Vulnerabilities Among 164 CVEs
Microsoft has addressed 164 vulnerabilities in its April 2026 security update release, double the number of vulnerabilities in March 2026. These include one exploited zero-day vulnerability, one previ ... Read more
-
The Cyber Express
Microsoft Fixes 167 Vulnerabilities in Latest Patch Tuesday Update
Microsoft’s Patch Tuesday April 2026 release has introduced one of the most extensive security update rollouts of the year, addressing a total of 167 vulnerabilities across Windows operating systems a ... Read more
-
TheCyberThrone
Microsoft Patch Tuesday — April 2026
TheCyberThrone | Vulnerability Advisory | April 15, 2026Volume & Scale — A Near-Record ReleaseMicrosoft patched 163 CVEs in the April 2026 Patch Tuesday release — the second largest Patch Tuesday on r ... Read more
The following table lists the changes that have been made to the
CVE-2026-23666 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.
-
Initial Analysis by [email protected]
May. 07, 2026
Action Type Old Value New Value Added CPE Configuration AND OR *cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:* OR cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:a:microsoft:.net_framework:4.7.2:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:* OR cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:x86:* Added CPE Configuration AND OR *cpe:2.3:a:microsoft:.net_framework:4.8:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:* OR cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:x86:* cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:x86:* cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:x86:* Added CPE Configuration AND OR *cpe:2.3:a:microsoft:.net_framework:3.5:-:*:*:*:*:*:* *cpe:2.3:a:microsoft:.net_framework:4.8.1:*:*:*:*:*:*:* OR cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_11_22h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:x86:* cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_10_22h2:-:*:*:*:*:*:x86:* cpe:2.3:o:microsoft:windows_11_22h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_11_23h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_11_23h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_11_24h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_11_24h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_server_2022_23h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_11_25h2:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_11_25h2:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_11_26h1:-:*:*:*:*:*:arm64:* cpe:2.3:o:microsoft:windows_11_26h1:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_server_2025:-:*:*:*:*:*:x64:* Added CPE Configuration AND OR *cpe:2.3:a:microsoft:.net_framework:4.6.2:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:.net_framework:4.7:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:.net_framework:4.7.1:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:.net_framework:4.7.2:*:*:*:*:*:*:* OR cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:a:microsoft:.net_framework:4.8:*:*:*:*:*:*:* OR cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1607:-:*:*:*:*:*:x64:* cpe:2.3:o:microsoft:windows_10_1607:-:*:*:*:*:*:x86:* Added Reference Type Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23666 Types: Vendor Advisory -
CVE Modified by [email protected]
Apr. 15, 2026
Action Type Old Value New Value Changed Description Concurrent execution using shared resource with improper synchronization ('race condition') in .NET Framework allows an unauthorized attacker to deny service over a network. Improper input validation in .NET Framework allows an unauthorized attacker to deny service over a network. -
New CVE Received by [email protected]
Apr. 14, 2026
Action Type Old Value New Value Added Description Concurrent execution using shared resource with improper synchronization ('race condition') in .NET Framework allows an unauthorized attacker to deny service over a network. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-755 Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23666