CVE-2026-102870
published 2026-10-13CVE-2026-102870: Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.
PriorityP356high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.91%
59.6th percentile
Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft.aspnetcore.components.webassembly.devserver | >= 11.0.0-preview.1 < 10.0.14 | 10.0.14 |
| microsoft | microsoft.aspnetcore.components.webassembly.server | >= 10.0.0 < 10.0.13 | 10.0.13 |
| microsoft | microsoft.aspnetcore.components.webassembly.server | >= 10.0.0 < 10.0.13 | 10.0.13 |
| microsoft | microsoft.aspnetcore.components.webassembly.server | >= 11.0.0-preview.1 < 11.0.0-rc.2.26478.115 | 11.0.0-rc.2.26478.115 |
| microsoft | microsoft_visual_studio_2019_version_16.11 | >= 16.11.0 < 16.11.61 | 16.11.61 |
| microsoft | microsoft_visual_studio_2022_version_17.14 | >= 17.14.0 < 17.14.43 | 17.14.43 |
| microsoft | microsoft_visual_studio_2026_version_18.10 | >= 18.10.0 < 18.10.4 | 18.10.4 |
| microsoft | microsoft_visual_studio_2026_version_18.11 | >= 18.11.0 < 18.11.2 | 18.11.2 |
| microsoft | microsoft_visual_studio_2026_version_18.12 | >= 18.12.0 < 18.12 Insiders 3 | 18.12 Insiders 3 |
| microsoft | net_10.0_installed_on_linux | >= 10.0.0 < 10.0.403 | 10.0.403 |
| microsoft | net_10.0_installed_on_mac_os | >= 10.0.0 < 10.0.403 | 10.0.403 |
| microsoft | net_10.0_installed_on_windows | >= 10.0.0 < 10.0.403 | 10.0.403 |
| microsoft | net_11.0_installed_on_linux | >= 11.0.0-preview.1 < 11.0.100-rc.3 | 11.0.100-rc.3 |
| microsoft | net_11.0_installed_on_mac_os | >= 11.0.0-preview.1 < 11.0.100-rc.3 | 11.0.100-rc.3 |
| microsoft | net_11.0_installed_on_windows | >= 11.0.0-preview.1 < 11.0.100-rc.3 | 11.0.100-rc.3 |
| ubuntu | dotnet10 | — | — |
| ubuntu | dotnet11 | — | — |
| ubuntu | dotnet8 | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
ghsa8.8HIGH
vendor_redhat8.8HIGH
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Ubuntu
.NET vulnerabilities
vendor_ubuntu·2026-10-20
CVE-2026-70188 .NET vulnerabilities
Title: .NET vulnerabilities
Summary: Several security issues were fixed in .NET.
Multiple security issues were discovered in .NET and this update includes
new upstream .NET versions to fix these issues.
.NET 8 has been updated to 8.0.32 in Ubuntu 22.04 LTS and Ubuntu 24.04 LTS.
.NET 10 has been updated to 10.0.13 in Ubuntu 24.04 LTS, Ubuntu 26.04 LTS
and Ubuntu 26.10. .NET 11 has been updated to 11.0.0~rc2 in Ubuntu 26.10.
In addition to security fixes, the updated packages contain bug fixes, new
features, and possibly incompatible changes.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
dotnet: dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability
vendor_redhat·2026-10-13·CVSS 8.8
CVE-2026-102870 [HIGH] CWE-94 dotnet: dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability
dotnet: dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability
Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.
Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.
Package: dotnet10.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet10.0 (Red Hat Enterprise Linux 8) - Affected
Package: dotnet10.0 (Red Hat Enterprise Linux 9) - Affected
Package: dotnet10.0 (Red Hat Hardened Images) - Not affected
Package: dotnet8.0 (Red Hat Hardened Images) - Not affected
GHSA
Microsoft Security Advisory CVE-2026-102870 - ASP.NET Core Remote Code Execution Vulnerability
ghsa·2026-10-13·CVSS 8.8
CVE-2026-102870 [HIGH] CWE-94 Microsoft Security Advisory CVE-2026-102870 - ASP.NET Core Remote Code Execution Vulnerability
Microsoft Security Advisory CVE-2026-102870 - ASP.NET Core Remote Code Execution Vulnerability
## Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in the Blazor WebAssembly debugger included in `Microsoft.AspNetCore.Components.WebAssembly.Server`. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
The Blazor WebAssembly debug proxy evaluates debugger expressions by generating and compiling C# source. Certain values originating in the application being debugged, including `ToString()` results, descriptions, and class names, are embedded in that generated source without consistent escaping. An attacker-controlled value can escape the generated string literal a
No detection rules found.
No public exploits indexed.
Sans Isc
October 2026 Microsoft Patch Tuesday, (Tue, Oct 13th)
blogs_sans_isc·2026-10-13·CVSS 8.8
CVE-2026-96951 [HIGH] October 2026 Microsoft Patch Tuesday, (Tue, Oct 13th)
October 2026 Microsoft Patch Tuesday
Published: 2026-10-13. Last Updated: 2026-10-13 19:25:52 UTC
by Johannes Ullrich (Version: 1)
0 comment(s)
Microsoft today released patches for 1,417 vulnerabilities. 76 of these vulnerabilities are rated critical, with 7 critical vulnerabiilties requiring no customer actions. One vulnerability was disclosed before today's patch Tuesday, and one is already exploited.
CVE-2026-96951: An already exploited Windows Shell Security Feature Bypass Vulnerability. This vulnerabliity allows bypassing the "Mark of the Web" making it easier to exeucte code by sending a malicious message to a user via e-mail or instant messaging. The victim will still have to open the file.
CVE-2026-108398: This vulnerability, a .NET framework security feature bypass, could be
Rapid7
Patch Tuesday - October 2026
blogs_rapid7·2026-10-13·CVSS 8.8
CVE-2026-96951 [HIGH] Patch Tuesday - October 2026
Microsoft is publishing 1,413 own-product vulnerabilities on October 2026 Patch Tuesday , including 1,102 vulnerabilities in Windows. Anyone who enjoyed last month’s record-setting Patch Tuesday will love the October 2026 edition, because it’s much bigger still. As Rapid7 has noted over the course of 2026, there is every reason to suppose that vulnerability volumes will continue to rise. Microsoft is aware of exploitation in the wild for just one of the vulnerabilities published today, as well as public disclosure for two others.
## Windows Shell: zero-day security feature bypass
The Windows Shell is Microsoft’s term for the GUI interaction logic for the entire OS provided by explorer.exe and associated libraries and APIs, and for the second time this year , the Windows Shell is the site
Bugzilla
CVE-2026-96959 dotnet10.0: .NET: Denial of Service via unthrottled resource allocation [fedora-43]
bugzilla·2026-10-23·CVSS 8.8
CVE-2026-96959 [HIGH] CVE-2026-96959 dotnet10.0: .NET: Denial of Service via unthrottled resource allocation [fedora-43]
CVE-2026-96959 dotnet10.0: .NET: Denial of Service via unthrottled resource allocation [fedora-43]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Allocation of resources without limits or throttling in .NET allows an unauthorized attacker to deny service over a network.
Discussion:
Closing/resolving as this was fixed in https://bodhi.fedoraproject.org/updates/FEDORA-2026-c7c459ff4d
Update to .NET SDK 10.0.113 and Runtime 10.0.13
Fixes: CVE-2026-102870,CVE-2026-105016,CVE-2026-58280,CVE-2026-66822,CVE-2026-69651,CVE-2026-70007,CVE-2026-70035,CVE-2026-70159,CVE-2026-70161,CVE-2026-70162,CVE-2026-70165,CVE-2026-7
Bugzilla
CVE-2026-102870 dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability [fedora-all]
bugzilla·2026-10-14·CVSS 8.8
CVE-2026-102870 [HIGH] CVE-2026-102870 dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability [fedora-all]
CVE-2026-102870 dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.
Affected packages:
- Microsoft.AspNetCore.Components.WebAssembly.Server (release 11.0): 11.0.0-preview.1 - 11.0.0-rc.1; fixed 11.0.0-rc.2.26478.115
- Microsoft.AspNetCore.Components.WebAssembly.Server (release 10.0): 10.0.0 - 10.0.12; fixed 10.0.13
Bugzilla
CVE-2026-102870 dotnet: dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability
bugzilla·2026-10-09·CVSS 8.8
CVE-2026-102870 [HIGH] CVE-2026-102870 dotnet: dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability
CVE-2026-102870 dotnet: dotnet10.0: ASP.NET Core Remote Code Execution Vulnerability
The Blazor WebAssembly debug proxy embeds attacker-controlled ToString(), description, and class-name values into generated C# without consistently escaping them. When a developer evaluates an expression while debugging, the value can escape the generated string literal and execute code on the developer's machine.
CNA: microsoft
CNA impact: Remote Code Execution
CWE: CWE-94
Platforms: all
Architectures: all
CVSS 3.1: 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
Affected packages:
- Microsoft.AspNetCore.Components.WebAssembly.Server (release 11.0): 11.0.0-preview.1 - 11.0.0-rc.1; fixed 11.0.0-rc.2.26478.115 [dotnet@34f96ff]
- Microsoft.AspNetCore.Components.WebAssembly.Server (release 10.0): 10.0.0
2026-10-13
Published