Security Vulnerabilities fixed in Firefox ESR 78.10 — Mozilla

A WebGL framebuffer was not initialized early enough, resulting in memory corruption and an out of bound write.
When Responsive Design Mode was enabled, it used references to objects that were previously freed. We presume that with enough effort this could have been exploited to run arbitrary code.
Through complicated navigations with new windows, an HTTP page could have inherited a secure lock icon from an HTTPS page.
Further techniques that built on the slipstream research combined with a malicious webpage could have exposed both an internal network’s hosts as well as services running on the user’s local machine.
If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to web content.
When a user clicked on an FTP URL containing encoded newline characters (%0A and %0D), the newlines would have been interpreted as such and allowed arbitrary commands to be sent to the FTP server.
The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and result in a crash. Note: This issue only affected x86-32 platforms. Other platforms are unaffected.
Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header.