Cisco Talos discloses technicals details of Chrome, Firefox flaws July 5, 2020 https://securityaffairs.co/wordpress/105547/security/talos-chrome-firefox-flaws.html
Weird, once again it's not clear if they were able to bypass the sandbox in both Chrome and Firefox. Normally, if they were able to run malware, it's still restricted by the sandbox, so it runs with low rights.
Leaked memory as I understand it is available but unallocated memory. In other words, it is no longer associated with the active browser process. As such, it is no longer inhibited by any restrictions employed by the leaker processes. Memory leaks are serious and other processes have been known to leak memory.
From what I understood, it's no longer enough for hackers to simply get remote code execution. They need to combine it with a second exploit that let's them escape the sandbox. This can be either a sandbox exploit in the browser or a Windows kernel exploit in the OS. For example, a tool like Sandboxie would most likely still contain the malware even if hackers used a sandbox exploit inside the browser.
