Remote Code Execution in Microsoft Defender Heap Buffer Overflow

Successful exploitation can result in remote code execution in the context of the affected Microsoft Defender component. Based on the provided CVSS v3.1 vector (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H), the vulnerability can have high impact on confidentiality, integrity, and availability, potentially allowing an attacker to fully compromise the affected service or host component, access sensitive data, modify data or security controls, and disrupt normal operation.

Specific mitigations are not provided in the available content. In the absence of a patch, prudent interim measures would include limiting unnecessary network exposure to systems or services that can deliver content to Microsoft Defender for scanning, enforcing network segmentation, monitoring for anomalous Defender-related crashes or exploitation attempts, and ensuring rapid deployment of Microsoft Defender updates. However, vendor-specific mitigation guidance is currently not available in the provided material.

The provided content indicates that Microsoft published guidance for CVE-2026-45584 in the MSRC Update Guide. Apply the vendor-provided security update for Microsoft Defender associated with CVE-2026-45584 as soon as it is available in your environment, and ensure Defender engines, platform components, and signatures are fully updated through normal Microsoft update channels. No more specific remediation details are available in the provided content.