CVE-2026-12437 is a use-after-free vulnerability in the WebShare feature of Google Chrome on Windows platforms. It affects versions prior to 149.0.7827.155. Exploitation requires that an attacker has already compromised the renderer process and can craft a malicious HTML page to trigger a sandbox escape. The vulnerability is critical in nature as it impacts confidentiality, integrity, and availability. Google has published a stable channel update that addresses this issue.

Successful exploitation could allow an attacker with control over the renderer process to escape the Chrome sandbox, potentially leading to full system compromise. The vulnerability affects confidentiality, integrity, and availability of the affected system. There are no known exploits in the wild at the time of this report.

Users and administrators should update Google Chrome on Windows to version 149.0.7827.155 or later to remediate this vulnerability. The vendor advisory indicates that this update fixes the issue. No additional mitigation steps are indicated by the vendor.