Texture upload into an unbound backing buffer resulted in an out-of-bound read. (CVE-2021-23981)
Angle graphics library out of date. (CVE-2021-4127)
Internal network hosts could have been probed by a malicious webpage. (CVE-2021-23982)
Malicious extensions could have spoofed popup information. (CVE-2021-23984)
Memory safety bugs fixed in Firefox 87 and Firefox ESR 78.9 (CVE-2021-23987).