CVE-2026-50655 – Microsoft Windows Media Foundation Remote Code Execution Vulnerability

A heap-based buffer overflow vulnerability in Microsoft Windows Media Foundation allows an unauthorized attacker to execute code locally. Although classified as a Remote Code Execution vulnerability, exploitation requires user interaction, such as opening a specially crafted media file. Successful exploitation could allow arbitrary code execution with the privileges of the current user, resulting in loss of confidentiality, integrity, and availability.

CVSS Score: 7.8

SEVERITY: Critical

THREAT:
This vulnerability affects Microsoft Windows Media Foundation, the multimedia framework used by Windows to process audio and video content. An attacker could deliver a specially crafted media file through email, messaging platforms, websites, or file-sharing services and convince a user to open it. Once processed, the malicious file could trigger memory corruption and execute attacker-controlled code on the affected system.

EXPLOITS:
The vulnerability was not publicly disclosed at the time of publication. Microsoft assesses exploitation as more likely. The CVSS v3.1 temporal metrics list exploit code maturity as Unproven, and the available information does not confirm the existence of publicly available proof-of-concept exploit code.

TECHNICAL SUMMARY:
The vulnerability is caused by a heap-based buffer overflow (CWE-122) in Microsoft Windows Media Foundation. Improper handling of specially crafted media content can corrupt memory, allowing arbitrary code execution. The CVSS v3.1 metrics identify a local attack vector, low attack complexity, no privileges required, and user interaction required. Microsoft notes that although the vulnerability is categorized as Remote Code Execution, the attack is performed locally after a user is persuaded to open malicious content, making social engineering a key part of the attack chain.

EXPLOITABILITY:
Affected products include Windows 10 versions 1607, 1809, 21H2, and 22H2, Windows 11 versions 24H2, 25H2, and 26H1, and Windows Server 2016, 2019, 2022, and 2025, including affected Server Core installations. Exploitation requires a user to open or process a specially crafted media file.

BUSINESS IMPACT:
Media files are commonly exchanged through email, collaboration platforms, and websites, making them an attractive delivery mechanism for attackers. Successful exploitation could enable malware installation, data theft, disruption of business operations, or provide an entry point for additional attacks within the organization.

WORKAROUND:
No mitigations or workarounds are available.

URGENCY:
This vulnerability should be prioritized because it is rated Critical. Microsoft also assesses exploitation as more likely, increasing the importance of deploying security updates promptly. User interaction is required, but malicious media files remain a common and effective attack vector.