Links in a sandboxed iframe could open an external app on Android without the required "allow-" permission. This vulnerability was fixed in Firefox 144 and Thunderbird 144.
Cookie storage for non-HTML temporary documents was being shared incorrectly with normal browsing content, allowing information from private tabs to escape Incognito mode even after the user closed all tabs. This vulnerability was fixed in Firefox for iOS 143.1.
Malicious scripts could bypass the popup blocker to spam new tabs, potentially resulting in denial of service attacks. This vulnerability was fixed in Firefox for iOS 142.
Firefox for iOS would not respect a Content-Disposition header of type Attachment and would incorrectly display the content inline rather than downloading, potentially allowing for XSS attacks. This vulnerability was fixed in Firefox for iOS 142.