CVE-2026-12454 is a race condition vulnerability in the Safe Browsing feature of Google Chrome on Mac platforms before version 149.0.7827.155. An attacker who has already compromised the renderer process can exploit this race condition to potentially perform a sandbox escape by delivering a specially crafted HTML page. This vulnerability could allow the attacker to break out of the sandbox containment, increasing the risk of further system compromise. The vulnerability is acknowledged by the Chromium project with a high severity rating. No CVSS score or explicit remediation level is provided in the available data. The vendor advisory URL points to a Chrome stable channel update announcement, but no explicit patch or remediation details are included in the input data.

If exploited, this vulnerability could allow an attacker with control over the renderer process to escape the Chrome sandbox on Mac systems. Sandbox escape increases the attacker's privileges and ability to affect the host system beyond the browser sandbox, potentially leading to broader system compromise. The vulnerability is rated as high severity by Chromium, indicating significant risk if exploited.

Patch status is not yet confirmed — check the vendor advisory at https://chromereleases.googleblog.com/2026/06/stable-channel-update-for-desktop_01750511403.html for current remediation guidance. Since the affected version is explicitly stated as =149.0.7827.155, users should update to a later version of Chrome where this issue is presumably fixed. Until then, avoid using the affected version and monitor official Google Chrome release notes for updates.