This vulnerability (CVE-2026-66312) involves a buffer over-read (CWE-126) in Microsoft Edge (Chromium-based), specifically version 1.0.0.0. It allows an attacker with authorized access to execute code remotely over a network. The vulnerability has a CVSS 3.1 base score of 6.5, reflecting medium severity with network attack vector, low attack complexity, and required privileges. Microsoft has released an official fix to address this issue as documented in their security update guide.

An authorized attacker can exploit this buffer over-read vulnerability to execute code remotely on the affected system running Microsoft Edge (Chromium-based) version 1.0.0.0. This could lead to unauthorized code execution without user interaction. There are no reports of active exploitation in the wild.

Apply the official security update provided by Microsoft for Microsoft Edge (Chromium-based) to remediate this vulnerability. Since an official fix is available, updating to the patched version is the recommended action. Refer to the Microsoft security update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66312 for detailed patch information and deployment instructions.