EXECUTIVE SUMMARY:
CVE-2026-3298 with a CVSS score of 8.8 is a high-severity memory safety vulnerability impacting the asyncio module in Python's standard library on Windows systems. The affected product is specifically the ProacterEventLoop, which is the default event loop implementation for Python on Windows, and the impacted versions include Python versions prior to 3.15.0. The vulnerability resides in the sock_recvfrom_into() method, where a missing boundary check for the data buffer allows an attacker to craft specific network traffic that corrupts adjacent memory through an "out-of-bounds buffer write", potentially leading to Remote Code Execution (RCE) or a complete application crash (Denial of Service). An attacker can exploit this vulnerability by sending a malicious network packet to a Python application utilizing the asyncio library, which is foundational for many modern Python web servers, chat applications, and networking tools, resulting in a significant business impact and consequences if exploited, including data breaches, system compromise, and reputational damage. The attack vector is a network-based exploit, requiring access to a vulnerable Python application on a Windows system, and non-Windows platforms are not affected.[/subscribe_to_unlock_form]
EXECUTIVE SUMMARY:
CVE-2026-3298 with a CVSS score of 8.8 is a high-severity memory safety vulnerability impacting the asyncio module in Python's standard library on Windows systems. The affected product is specifically the ProacterEventLoop, which is the default event loop implementation for Python on Windows, and the impacted versions include Python versions prior to 3.15.0. The vulnerability resides in the sock_recvfrom_into() method, where a missing boundary check for the data buffer allows an attacker to craft specific network traffic that corrupts adjacent memory through an "out-of-bounds buffer write", potentially leading to Remote Code Execution (RCE) or a complete application crash (Denial of Service). An attacker can exploit this vulnerability by sending a malicious network packet to a Python application utilizing the asyncio library, which is foundational for many modern Python web servers, chat applications, and networking tools, resulting in a significant business impact and consequences if exploited, including data breaches, system compromise, and reputational damage. The attack vector is a network-based exploit, requiring access to a vulnerable Python application on a Windows system, and non-Windows platforms are not affected.[emaillocker id="1283"]
RECOMMENDATION:
We recommend you to update Python to version 3.15.0 or later.
REFERENCES:
The following reports contain further technical details:
https://securityonline.info/python-asyncio-windows-vulnerability-cve-2026-3298/