Firefox for Android would become unstable and hard-to-recover when a website opened too many popups. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 89.

Repeated calls to the history and location interfaces could have been used to hang the browser. This was addressed by introducing rate-limiting to these API calls. This vulnerability affects Firefox < 83.

It was possible to move the cursor using pointerlock from an iframe. This allowed moving the cursor outside of the viewport and the Firefox window. This vulnerability affects Firefox < 128 and Thunderbird < 128.

A select option could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions. *This issue only affects Android versions of Firefox.* This vulnerability affects Firefox < 129.

Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

A malicious website could have included an iframe with an malformed URI resulting in a non-exploitable browser crash. This vulnerability affects Firefox < 126.

Malicious scripts could cause desynchronization between the address bar and web content before a response is received in Firefox iOS, allowing attacker-controlled pages to be presented under spoofed domains. This vulnerability was fixed in Firefox for iOS 147.4.

Unicode RTLO characters could allow malicious websites to spoof filenames in the downloads UI for Firefox for iOS, potentially tricking users into saving files of an unexpected file type. This vulnerability was fixed in Firefox for iOS 144.0.

Spoofing issue in Thunderbird. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.

In certain scenarios a malicious website could attempt to display a fake location URL bar which could mislead users as to the actual website address This vulnerability affects Firefox for iOS < 127.

Malicious scripts that interrupt new tab page loading could cause desynchronization between the address bar and page content, allowing the attacker to spoof arbitrary HTML under a trusted domain. This vulnerability was fixed in Firefox for iOS 147.2.1.

In the address bar, Firefox for Android truncated the display of URLs from the end instead of prioritizing the origin. This vulnerability was fixed in Firefox 141.

Spoofing issue in the Address Bar component. This vulnerability was fixed in Firefox 142 and Firefox ESR 140.2.

Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

Spoofing issue in the Address Bar component of Firefox Focus for Android. This vulnerability was fixed in Firefox 142.

Focus incorrectly truncated URLs towards the beginning instead of around the origin. This vulnerability was fixed in Firefox 141.

A bug in popup notifications delay calculation could have made it possible for an attacker to trick a user into granting permissions. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

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 trick the user. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 97.

A crafted URL using a blob: URI could have hidden the true origin of the page, resulting in a potential spoofing attack. *Note: This issue only affected Android operating systems. Other operating systems are unaffected.*. This vulnerability was fixed in Firefox 141.

The Firefox and Firefox Focus UI for the Android custom tab feature only showed the "site" that was loaded, not the full hostname. User supplied content hosted on a subdomain of a site could have been used to fool a user into thinking it was content from a different subdomain of that site. This vulnerability was fixed in Firefox 144.

A malicious website that could create a popup could have resized the popup to overlay the address bar with its own content, resulting in potential user confusion or spoofing attacks. <br>*This bug only affects Thunderbird for Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

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.

Malicious scripts could display attacker-controlled web content under spoofed domains in Focus for iOS by stalling a _self navigation to an invalid port and triggering an iframe redirect, causing the UI to display a trusted domain without user interaction. This vulnerability was fixed in Focus for iOS 148.2.

A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. This vulnerability was fixed in Thunderbird 128.11.1 and Thunderbird 139.0.2.

Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage. This vulnerability was fixed in Focus 138.

When the address bar was hidden due to scrolling on Android, a malicious page could create a fake address bar to fool the user in response to a visibilitychange event. This vulnerability was fixed in Firefox 144.

Opening links via the contextual menu in Focus iOS for certain URL schemes would fail to load but would not refresh the toolbar correctly, allowing attackers to spoof websites if users were coerced into opening a link explicitly through a long-press. This vulnerability was fixed in Focus for iOS 143.0.

By manipulating the fullscreen feature while opening a data-list, an attacker could have overlaid a text box over the address bar. This could have led to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 127.

A specially crafted filename containing a large number of encoded newline characters could obscure the file's extension when displayed in the download dialog. *This bug only affects Thunderbird for Android. Other versions of Thunderbird are unaffected.*. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

Through a series of popup and <code>window.print()</code> calls, an attacker can cause a window to go fullscreen without the user seeing the notification prompt, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox ESR < 102.5, Thunderbird < 102.5, and Firefox < 107.

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources. This vulnerability was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.

The date picker could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, Firefox ESR < 128.1, Thunderbird < 128.1, and Thunderbird < 115.14.

Insufficient policy enforcement in browser UI in Google Chrome prior to 147.0.7727.55 allowed a remote attacker who had compromised the renderer process to perform UI spoofing via a crafted HTML page. (Chromium security severity: Medium)

Inappropriate implementation in WebApp Installs in Google Chrome on Android prior to 134.0.6998.35 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Low)

User Interface (UI) Misrepresentation of Critical Information vulnerability in Drupal Drupal core allows Content Spoofing.This issue affects Drupal core: from 8.0.0 before 10.4.9, from 10.5.0 before 10.5.6, from 11.0.0 before 11.1.9, from 11.2.0 before 11.2.8.

Inappropriate implementation in Fullscreen in Google Chrome prior to 128.0.6613.84 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Medium)

Inappropriate implementation in Intents in Google Chrome on Android prior to 129.0.6668.58 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Low)

Inappropriate implementation in Compositing in Google Chrome prior to 140.0.7339.80 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Low)

Inappropriate implementation in Autofill in Google Chrome on Windows prior to 124.0.6367.60 allowed a remote attacker to perform UI spoofing via a crafted HTML page. (Chromium security severity: Medium)

A spoofing issue was addressed with improved truncation when displaying the fully qualified domain name. This issue is fixed in Safari 18.5, macOS Sequoia 15.5. A website may be able to spoof the domain name in the title of a pop-up window.