Web-accessible extension pages (pages with a moz-extension:// scheme) were not correctly enforcing the frame-ancestors directive when it was used in the Web Extension’s Content Security…

Under certain circumstances, a JavaScript alert (or prompt) could have been shown while another website was displayed underneath it. This could have been abused to…

When a worker is shutdown, it was possible to cause script to run late in the lifecycle, at a point after where it should not…

Mozilla developers Paul Adenot and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 96 and Firefox ESR 91.5. Some of these bugs…

When clicking on a tel: link, USSD codes, specified after a <code>*</code> character, would be included in the phone number. On certain phones, or on…

If a document created a sandboxed iframe without <code>allow-scripts</code>, and subsequently appended an element to the iframe’s document that e.g. had a JavaScript event handler…

When importing resources using Web Workers, error messages would distinguish the difference between <code>application/javascript</code> responses and non-script responses. This could have been abused to learn…

By using XSL Transforms, a malicious webserver could have served a user an XSL document that would continue to execute JavaScript (within the bounds of…

If a user was convinced to drag and drop an image to their desktop or other folder, the resulting object could have been changed into…

Remote Agent, used in WebDriver, did not validate the Host or Origin headers. This could have allowed websites to connect back locally to the user’s…