CVE-2026-70354
Summary
by MITRE • 08/11/2026
Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical security flaw in the .NET runtime environment that enables remote code execution through an out-of-bounds write condition. The technical implementation involves memory corruption that occurs when the runtime fails to properly validate array bounds during memory operations, allowing attackers to write data beyond allocated memory regions. Such flaws typically arise from insufficient input validation and boundary checking mechanisms within the managed code execution environment, creating opportunities for malicious actors to manipulate memory layout and potentially overwrite critical program structures or function pointers.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables local code execution without requiring elevated permissions, making it particularly dangerous in environments where .NET applications are frequently deployed. Attackers can leverage this weakness to inject malicious payloads into memory segments that are subsequently executed by the runtime, effectively bypassing standard security controls such as address space layout randomization and data execution prevention mechanisms. This type of vulnerability commonly maps to CWE-787 Out-of-bounds Write within the Common Weakness Enumeration framework, which specifically addresses improper bounds checking in memory operations.
The attack surface for this vulnerability encompasses any system running .NET applications that process untrusted input through array-based operations or memory allocation functions. Modern exploitation techniques often involve crafting specific input sequences that trigger the out-of-bounds write condition, followed by careful manipulation of the memory layout to achieve code execution. This approach aligns with tactics described in the MITRE ATT&CK framework under T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, as attackers can leverage such vulnerabilities to establish persistent access or escalate privileges within compromised systems.
Mitigation strategies should focus on implementing robust input validation, enabling runtime protections such as .NET's built-in security features including control flow integrity checks, and ensuring timely patch management across all affected platforms. Organizations should also consider deploying application whitelisting policies that restrict execution of untrusted .NET assemblies and implement memory protection mechanisms that prevent unauthorized code injection. Regular security assessments and code reviews specifically targeting array boundary conditions and memory management practices can help identify similar vulnerabilities before they can be exploited in production environments.