An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability was fixed in Firefox 140 and Thunderbird 140.

Focus was incorrectly allowing internal links to utilize the app scheme used for deeplinking, which could result in links potentially circumventing some URL safety checks This vulnerability affects Focus for iOS < 132.

The QR scanner could allow arbitrary websites to be opened if a user was tricked into scanning a malicious link that leveraged Firefox's open-text URL scheme. This vulnerability was fixed in Firefox for iOS 141.

A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended frame, potentially enabling a sandbox escape. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.

Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

Undefined behavior in the Audio/Video component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

Under certain circumstances, a user opt-in setting that Focus should require authentication before use could have been be bypassed (distinct from CVE-2025-0245). This vulnerability was fixed in Firefox 136.

Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

Same-origin policy bypass in the Networking: DNS component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

When switching between Android apps using the card carousel Firefox shows a black screen as its card image when a password-related screen was the last one being used. Prior to Firefox 144 the password edit screen was visible. This vulnerability was fixed in Firefox 144.

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. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Different techniques existed to obscure the fullscreen notification in Firefox and Focus for Android. These could have led to potential user confusion and spoofing attacks. *This bug only affects Firefox and Focus for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox for Android < 112 and Focus for Android < 112.

Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

Setting a nameless cookie with an equals sign in the value shadowed other cookies. Even if the nameless cookie was set over HTTP and the shadowed cookie included the `Secure` attribute. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.

A malicious website could have used a combination of exiting fullscreen mode and `requestPointerLock` to cause the user's mouse to be re-positioned unexpectedly, which could have led to user confusion and inadvertently granting permissions they did not intend to grant. This vulnerability affects Firefox < 123, Firefox ESR < 115.8, and Thunderbird < 115.8.

A crafted URL containing Arabic script and whitespace characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.

Malicious websites may have been able to perform user intent confirmation through tapjacking. This could have led to users unknowingly approving the launch of external applications, potentially exposing them to underlying vulnerabilities. This vulnerability affects Firefox < 133 and Thunderbird < 133.

The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially allowing an attacker to trick a user into granting an exception and loading a webpage over HTTP. This vulnerability was fixed in Firefox 140 and Thunderbird 140.

A missing delay in directory upload UI could have made it possible for an attacker to trick a user into granting permission via clickjacking. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

When reusing existing popups Firefox would have allowed them to cover the fullscreen notification UI, which could have enabled browser spoofing attacks. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.

An improper implementation of the new iframe sandbox keyword <code>allow-top-navigation-by-user-activation</code> could lead to script execution without <code>allow-scripts</code> being present. This vulnerability affects Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.

When receiving an HTML email that specified to load an <code>iframe</code> element from a remote location, a request to the remote document was sent. However, Thunderbird didn't display the document. This vulnerability affects Thunderbird < 102.2.1 and Thunderbird < 91.13.1.

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.

It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Cross-origin iframes that contained a login form could have been recognized by the login autofill service, and populated. This could have been used in clickjacking attacks, as well as be read across partitions in dynamic first party isolation. This vulnerability affects Firefox < 83.

The timing of a button click causing a popup to disappear was approximately the same length as the anti-clickjacking delay on permission prompts. It was possible to use this fact to surprise users by luring them to click where the permission grant button would be about to appear. This vulnerability affects Firefox ESR < 115.6 and Firefox < 121.

If an attacker needed a user to load an insecure http: page and knew that user had enabled HTTPS-only mode, the attacker could have tricked the user into clicking to grant an HTTPS-only exception if they could get the user to participate in a clicking game. This vulnerability affects Firefox < 120.

It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an insufficient activation-delay. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.

A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.

The permission request prompt from the site in the background tab was overlaid on top of the site in the foreground tab. This vulnerability affects Firefox for iOS < 115.

A background script invoking <code>requestFullscreen</code> and then blocking the main thread could force the browser into fullscreen mode indefinitely, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

The fullscreen notification could have been hidden on Firefox for Android by using download popups, resulting in potential user confusion or spoofing attacks. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 111.

The file-download implementation in Mozilla Firefox before 27.0 and SeaMonkey before 2.24 does not properly restrict the timing of button selections, which allows remote attackers to conduct clickjacking attacks, and trigger unintended launching of a downloaded file, via a crafted web site.

Mozilla Firefox before 27.0 and SeaMonkey before 2.24 allow remote attackers to bypass the Same Origin Policy and obtain sensitive information by using an IFRAME element in conjunction with certain timing measurements involving the document.caretPositionFromPoint and document.elementFromPoint functions.

Mozilla Firefox before 26.0 and SeaMonkey before 2.23 do not properly consider the sandbox attribute of an IFRAME element during processing of a contained OBJECT element, which allows remote attackers to bypass intended sandbox restrictions via a crafted web site.

Mozilla Firefox before 25 allows modification of anonymous content of pluginProblem.xml binding

Service Workers did not detect Private Browsing Mode correctly in all cases, which could have led to Service Workers being written to disk for websites visited in Private Browsing Mode. This would not have persisted them in a state where they would run again, but it would have leaked Private Browsing Mode details to disk. This vulnerability affects Firefox < 107.

If a custom mouse cursor is specified in CSS, under certain circumstances the cursor could have been drawn over the browser UI, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox ESR < 102.5, Thunderbird < 102.5, and Firefox < 107.

Use tables inside of an iframe, an attacker could have caused iframe contents to be rendered outside the boundaries of the iframe, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox ESR < 102.5, Thunderbird < 102.5, and Firefox < 107.

Clickjacking issue in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 153.

Clickjacking issue in the Widget: Gtk component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.