Linux Kernel Vulnerability in TLS Stream Handling

CVE-2025-39946

What is CVE-2025-39946?

CVE-2025-39946 is a vulnerability found in the Linux kernel that affects the handling of TLS (Transport Layer Security) streams. The Linux kernel, a core component of many operating systems, is crucial for managing hardware-software interactions and ensuring system stability. This vulnerability arises when the kernel mismanages the processing of TLS stream headers, leading to a scenario where an invalid record could result in a buffer overflow. Such a flaw can create severe security risks, as it may allow attackers to exploit the vulnerability and potentially execute arbitrary code within the affected system. The handling error occurs specifically when records are read prematurely, complicating the ability to abort connections when encountering invalid data.

Potential impact of CVE-2025-39946

1. Arbitrary Code Execution: The primary concern with CVE-2025-39946 is that it facilitates the potential for attackers to execute arbitrary code on affected systems, which can lead to unauthorized access and control over sensitive data.

2. Denial of Service: Attackers can exploit this vulnerability to create conditions that cause the affected systems to become unresponsive, leading to denial-of-service situations that disrupt normal operations and incapacitate services.

3. Data Integrity Compromise: Given that this vulnerability affects TLS stream handling, it poses a significant risk to data integrity. Man-in-the-middle attacks could be facilitated, where attackers could alter or inject malicious data into communications protected by TLS, thereby compromising the trustworthiness of transmitted information.

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