CVE-2026-87589 is an authorization bypass vulnerability in Google Chrome's SiteIsolation feature affecting versions prior to 153.0.8010.36. A remote attacker who has already compromised the renderer process can exploit this flaw via a crafted HTML page to bypass system access restrictions. The vulnerability is categorized under CWE-863 (Incorrect Authorization). There is no CVSS score provided, and no patch or vendor advisory details are currently available. No known active exploitation has been reported.

The vulnerability allows an attacker with control over the renderer process to bypass system access restrictions, potentially escalating privileges or accessing restricted system resources. The impact is limited to scenarios where the attacker has already compromised the renderer process. No evidence of active exploitation is known.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should follow best practices to limit renderer process compromise, such as avoiding untrusted content and maintaining updated security configurations.