In unusual circumstances, selecting text could cause text selection caching to behave incorrectly, leading to a crash. This vulnerability affects Firefox < 99.

Due to a layout change, iframe contents could have been rendered outside of its border. This could have led to user confusion or spoofing attacks. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.

When generating the assembly code for <code>MLoadTypedArrayElementHole</code>, an incorrect AliasSet was used. In conjunction with another vulnerability this could have been used for an out of bounds memory read. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.

SVG's <code>&lt;use&gt;</code> element could have been used to load unexpected content that could have executed script in certain circumstances. While the specification seems to allow this, other browsers do not, and web developers relied on this property for script security so gecko's implementation was aligned with theirs. This vulnerability affects Firefox < 99.

The sourceMapURL feature in devtools was missing security checks that would have allowed a webpage to attempt to include local files or other files that should have been inaccessible. This vulnerability affects Firefox < 99.

By using a link with <code>rel="localization"</code> a use-after-free could have been triggered by destroying an object during JavaScript execution and then referencing the object through a freed pointer, leading to a potential exploitable crash. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.

If a compromised content process sent an unexpected number of WebAuthN Extensions in a Register command to the parent process, an out of bounds write would have occurred leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.

An unexpected message in the WebGPU IPC framework could lead to a use-after-free and exploitable sandbox escape. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.

Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.

When installing an add-on, Firefox verified the signature before prompting the user; but while the user was confirming the prompt, the underlying add-on file could have been modified and Firefox would not have noticed. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.

In unusual circumstances, an individual thread may outlive the thread's manager during shutdown. This could have led to a use-after-free causing a potentially exploitable crash. This vulnerability affects Firefox < 98.

If an attacker could control the contents of an iframe sandboxed with <code>allow-popups</code> but not <code>allow-scripts</code>, they were able to craft a link that, when clicked, would lead to JavaScript execution in violation of the sandbox. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.

When resizing a popup after requesting fullscreen access, the popup would not display the fullscreen notification. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.

While the text displayed in Autofill tooltips cannot be directly read by JavaScript, the text was rendered using page fonts. Side-channel attacks on the text by using specially crafted fonts could have lead to this text being inferred by the webpage. This vulnerability affects Firefox < 98.

An attacker could have caused a use-after-free by forcing a text reflow in an SVG object leading to a potentially exploitable crash. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.

The search term could have been specified externally to trigger SQL injection. This vulnerability affects Firefox for iOS < 101.

If an attacker was able to corrupt the methods of an Array object in JavaScript via prototype pollution, they could have achieved execution of attacker-controlled JavaScript code in a privileged context. This vulnerability affects Firefox ESR < 91.9.1, Firefox < 100.0.2, Firefox for Android < 100.3.0, and Thunderbird < 91.9.1.

An attacker could have sent a message to the parent process where the contents were used to double-index into a JavaScript object, leading to prototype pollution and ultimately attacker-controlled JavaScript executing in the privileged parent process. This vulnerability affects Firefox ESR < 91.9.1, Firefox < 100.0.2, Firefox for Android < 100.3.0, and Thunderbird < 91.9.1.

<code>NSSToken</code> objects were referenced via direct points, and could have been accessed in an unsafe way on different threads, leading to a use-after-free and potentially exploitable crash. This vulnerability affects Thunderbird < 91.8, Firefox < 99, and Firefox ESR < 91.8.

The HTTP/2 protocol does not consider the role of the TCP congestion window in providing information about content length, which makes it easier for remote attackers to obtain cleartext data by leveraging a web-browser configuration in which third-party cookies are sent, aka a "HEIST" attack.