Vulnerabilities

The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts or navigating the top-level frame.

When interacting with an HTML input element's file picker dialog with webkitdirectory set, a use-after-free could have resulted, leading to memory corruption and a potentially exploitable crash.

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user.

The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted c…

By displaying a form validity message in the correct location at the same time as a permission prompt (such as for geolocation), the validity message could have obscured the prompt, resulting in the user potentially bein…

Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing.

Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2.

A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash.

Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL.

An incorrect type conversion of sizes from 64bit to 32bit integers allowed an attacker to corrupt memory leading to a potentially exploitable crash.

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks.

Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers.

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped.

Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols.

Documents loaded with the CSP sandbox directive could have escaped the sandbox's script restriction by embedding additional content.

Using the Location API in a loop could have caused severe application hangs and crashes.

It was possible to recreate previous cursor spoofing attacks against users with a zoomed native cursor.