CVE-2026-100818

A critical use-after-free vulnerability in the Widget: Gtk component of Firefox allows for sandbox escape, potentially enabling attackers to execute arbitrary code outside of the browser's security confines. Organizations using affected versions of Firefox should prioritize patching to mitigate the risk of exploitation, particularly those in environments where web applications are accessed frequently. Immediate updates to Firefox ESR 153.4, Firefox 157, or Firefox ESR 140.17 are recommended to address this security flaw.