CVE-2026-91727 describes an incorrect reference resolution vulnerability in the Extensions component of Google Chrome on Mac systems before version 153.0.8010.47. This flaw enables a local attacker, who has already compromised the renderer process, to execute arbitrary code outside the sandbox via a local program. The vulnerability is classified with a CVSS 3.1 score of 8.1, indicating high impact on confidentiality, integrity, and availability.

Successful exploitation allows arbitrary code execution outside the sandbox by a local attacker with access to the compromised renderer process. This can lead to full system compromise on affected Mac systems running vulnerable Chrome versions.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability affects versions prior to 153.0.8010.47, so updating to version 153.0.8010.47 or later is expected to address the issue once the vendor confirms the fix.