Microsoft Net Framework 4.0 V 30319 Vulnerabilities Jun 2026

This is an obscure but severe flaw in how System.Data.DataView processes row filter expressions. If an application allows user input to affect a row filter string without sanitization, an attacker can inject specially crafted expressions that cause memory corruption.

The .NET Framework 4.5 and higher serve as in-place updates to .NET 4.0. Upgrading the underlying server host to .NET Framework 4.8 or 4.8.1 replaces the legacy binaries within the v4.0.30319 directory with secure, modern versions. In the vast majority of cases, legacy .NET 4.0 applications will run seamlessly on .NET 4.8 without code changes due to strict backward compatibility. Disable Dangerous Deserialization Features

: This is the current, fully supported version. It includes all security fixes for the issues mentioned above and receives monthly patches via Windows Update. You can find the latest version on the official .NET Download page .

The team also decided to upgrade to a newer version of the .NET Framework, one that had built-in security features and was more resilient to attacks. They spent several months planning and testing the upgrade, and eventually, they successfully completed the migration. microsoft net framework 4.0 v 30319 vulnerabilities

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It is important to note that refers to the CLR, not just .NET 4.0.

It is important to distinguish between the and the CLR (Common Language Runtime) version . This is an obscure but severe flaw in how System

is the underlying execution engine that compiles and runs the code.

Before diving into vulnerabilities, it is crucial to understand what 4.0.30319 represents. This number is the and the assembly file version of the core libraries. Early versions of .NET 4.0 (RTM) had build numbers like 4.0.30319.1 (RTM) and later 4.0.30319.269 (with updates).

Automated vulnerability assessment tools look at application metadata, responses, or local files and find the version identifier 4.0.30319 . This causes tools to report that the application is running unpatched Microsoft .NET Framework 4.0, exposing the host to historic exploits. Upgrading the underlying server host to

: An elevation of privilege flaw allowing malicious code injection.

| CVE ID | Vulnerability | CVSS Score (Base) | |--------|---------------|------------------| | | .NET Framework Security Feature Bypass (Insecure deserialization in remoting) | 7.8 (High) | | CVE-2012-1895 | .NET Framework Remoting Elevation of Privilege | 9.1 (Critical) |

: Remote attackers can inject malicious scripts or HTML into web applications via crafted values, leading to an elevation of privilege.

If an application is forced to run specifically on .NET 4.0 RTM (not a later in-place update), it remains vulnerable to the following high-impact CVEs:

Deploy an EDR that hooks .NET ETW (Event Tracing for Windows) providers: