Security Vulnerabilities fixed in Firefox ESR 128.1 — Mozilla

Select options could obscure the fullscreen notification dialog. This could be used by a malicious site to perform a spoofing attack.
Insufficient checks when processing graphics shared memory could have led to memory corruption. This could be leveraged by an attacker to perform a sandbox escape.
A type confusion bug in WebAssembly could be leveraged by an attacker to potentially achieve code execution.
Incomplete WebAssembly exception handing could have led to a use-after-free.
Editor code failed to check an attribute value. This could have led to an out-of-bounds read.
Firefox adds web-compatibility shims in place of some tracking scripts blocked by Enhanced Tracking Protection. On a site protected by Content Security Policy in “strict-dynamic” mode, an attacker able to inject an HTML element could have used a DOM Clobbering attack on some of the shims and achieved XSS, bypassing the CSP strict-dynamic protection.
It was possible for a web extension with minimal permissions to create a StreamFilter which could be used to read and modify the response body of requests on any site.
ANGLE failed to initialize parameters which led to reading from uninitialized memory. This could be leveraged to leak sensitive data from memory.
Unexpected marking work at the start of sweeping could have led to a use-after-free.
Incorrect garbage collection interaction in IndexedDB could have led to a use-after-free.
The date picker could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions.
Calling PK11_Encrypt() in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change.