CVE-2026-16358

A critical site isolation vulnerability in the Graphics: WebRender component of Firefox could allow attackers to exploit the flaw, potentially leading to unauthorized access to sensitive data across different sites. Users of affected versions of Firefox and Thunderbird should prioritize updating to the patched releases (Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13) to mitigate the risk. Organizations relying on these applications should take immediate action to ensure their systems are secure against potential exploitation.