An attacker could have written a value to the first element in a zero-length JavaScript array. Although the array was zero-length, the value was not written to an invalid memory address. This vulnerability affects Firefox < 104.

By holding a reference to the eval() function from an about:blank window, a malicious webpage could have gained access to the InstallTrigger object which would allow them to prompt the user to install an extension. Combined with user confusion, this could result in an unintended or malicious extension being installed. This vulnerability affects Firefox < 80, Thunderbird < 78.2, Thunderbird < 68.12, Firefox ESR < 68.12, Firefox ESR < 78.2, and Firefox for Android < 80.

If a user installed an extension of a particular type, the extension could have auto-updated itself and while doing so, bypass the prompt which grants the new version the new requested permissions. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.

Spoofing issue in the Address Bar component. This vulnerability affects Firefox < 142 and Firefox ESR < 140.2.

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

Malicious websites could have confused Firefox into showing the wrong origin when asking to launch a program and handling an external URL protocol. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.

When a link can be opened in an external application, Firefox for Android will, by default, prompt the user before doing so. An attacker could have bypassed this prompt, potentially exposing the user to security vulnerabilities or privacy leaks in external applications. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140.

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 browser to control it. <br>*This bug only affected Firefox when WebDriver was enabled, which is not the default configuration.*. This vulnerability affects Firefox < 97.

An OpenPGP digital signature includes information about the date when the signature was created. When displaying an email that contains a digital signature, the email's date will be shown. If the dates were different, then Thunderbird didn't report the email as having an invalid signature. If an attacker performed a replay attack, in which an old email with old contents are resent at a later time, it could lead the victim to believe that the statements in the email are current. Fixed versions of Thunderbird will require that the signature's date roughly matches the displayed date of the email. This vulnerability affects Thunderbird < 102 and Thunderbird < 91.11.

Malicious websites could have tricked users into accepting launching a program to handle an external URL protocol. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox < 95.

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities. This vulnerability affects Thunderbird < 91.4.0.

Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

Dragging a URL from a cross-origin iframe that was removed during the drag could have led to user confusion and website spoofing attacks. This vulnerability affects Firefox < 111, Firefox ESR < 102.9, and Thunderbird < 102.9.

When a ServiceWorker intercepted a request with <code>FetchEvent</code>, the origin of the request was lost after the ServiceWorker took ownership of it. This had the effect of negating SameSite cookie protections. This was addressed in the spec and then in browsers. This vulnerability affects Firefox ESR < 102.5, Thunderbird < 102.5, and Firefox < 107.

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.

Through a series of popups that reuse windowName, 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.

Long hostnames in URLs could be leveraged to obscure the actual host of the website or spoof the website address This vulnerability affects Firefox for iOS < 134.

By injecting a cookie with certain special characters, an attacker on a shared subdomain which is not a secure context could set and thus overwrite cookies from a secure context, leading to session fixation and other attacks. This vulnerability affects Firefox ESR < 102.3, Thunderbird < 102.3, and Firefox < 105.

An attacker could have abused XSLT error handling to associate attacker-controlled content with another origin which was displayed in the address bar. This could have been used to fool the user into submitting data intended for the spoofed origin. This vulnerability affects Thunderbird < 102.2, Thunderbird < 91.13, Firefox ESR < 91.13, Firefox ESR < 102.2, and Firefox < 104.

When in an endless loop, a website specifying a custom cursor using CSS could make it look like the user is interacting with the user interface, when they are not. This could lead to a perceived broken state, especially when interactions with existing browser dialogs and warnings do not work. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Thunderbird displayed an incorrect sender address if the From field of an email used the invalid group name syntax that is described in CVE-2024-49040. This vulnerability affects Thunderbird < 128.7 and Thunderbird < 135.

When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose what application to open it in. An attacker could induce that prompt to be associated with an origin they didn't control, resulting in a spoofing attack. This was fixed by changing external protocol prompts to be tab-modal while also ensuring they could not be incorrectly associated with a different origin. This vulnerability affects Firefox < 82.

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.

The executable file warning was not presented when downloading .atloc and .ftploc files, which can run commands on a user's computer. <br>*Note: This issue only affected Mac OS operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 108, Firefox ESR < 102.6, and Thunderbird < 102.6.

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.

A malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

When receiving an OpenPGP/MIME signed email message that contains an additional outer MIME message layer, for example a message footer added by a mailing list gateway, Thunderbird only considered the inner signed message for the signature validity. This gave the false impression that the additional contents were also covered by the digital signature. Starting with Thunderbird version 91.4.1, only the signature that belongs to the top level MIME part will be considered for the displayed status. This vulnerability affects Thunderbird < 91.4.1.

The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP address (e.g. port 8443) did not opt-in to opportunistic encryption; a network attacker could forward a connection from the browser to port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. This was resolved by disabling the Opportunistic Encryption feature, which had low usage. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to possible user confusion and spoofing attacks. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

When delegating navigations to the operating system, Firefox would accept the `mk` scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. *This bug only affects Firefox for Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 92, Thunderbird < 91.1, Thunderbird < 78.14, Firefox ESR < 78.14, and Firefox ESR < 91.1.

Mixed-content checks were unable to analyze opaque origins which led to some mixed content being loaded. This vulnerability affects Firefox < 92.

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.

Firefox for Android could get stuck in fullscreen mode and not exit it even after normal interactions that should cause it to exit. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 91.

When browsing private tabs, some data related to location history or webpage thumbnails could be persisted incorrectly within the sandboxed app bundle after app termination This vulnerability affects Firefox for iOS < 127.

A flaw in Mozilla's embedded certificate code might allow web sites to install root certificates on devices without user approval.

Through a series of DOM manipulations, a message, over which the attacker had control of the text but not HTML or formatting, could be overlaid on top of another domain (with the new domain correctly shown in the address bar) resulting in possible user confusion. This vulnerability affects Firefox < 90.

Through a series of API calls and redirects, an attacker-controlled alert dialog could have been displayed on another website (with the victim website's URL shown). This vulnerability affects Firefox < 123, Firefox ESR < 115.8, and Thunderbird < 115.8.

When a JavaScript URL (javascript:) is evaluated and the result is a string, this string is parsed to create an HTML document, which is then presented. Previously, this document's URL (as reported by the document.location property, for example) was the originating javascript: URL which could lead to spoofing attacks; it is now correctly the URL of the originating document. This vulnerability affects Firefox < 74.

When accessing throttled streams, the count of available bytes needed to be checked in the calling function to be within bounds. This may have lead future code to be incorrect and vulnerable. This vulnerability affects Firefox < 111, Firefox ESR < 102.9, and Thunderbird < 102.9.

If the user added a security exception for an invalid TLS certificate, opened an ongoing TLS connection with a server that used that certificate, and then deleted the exception, Firefox would have kept the connection alive, making it seem like the certificate was still trusted. This vulnerability affects Firefox < 107.

Missing thread synchronization primitives could have led to a data race on members of the PlaybackParams structure. This vulnerability affects Firefox < 133 and Thunderbird < 133.

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.

A clipboard "paste" button could persist across tabs which allowed a spoofing attack. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.

Truncation of a long URL could have allowed origin spoofing in a permission prompt. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.

When a parent page loaded a child in an iframe with `unsafe-inline`, the parent Content Security Policy could have overridden the child Content Security Policy. This vulnerability affects Firefox < 122, Firefox ESR < 115.7, and Thunderbird < 115.7.

The `VideoBridge` allowed any content process to use textures produced by remote decoders. This could be abused to escape the sandbox. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

A `&lt;dialog>` element could have been manipulated to paint content outside of a sandboxed iframe. This could allow untrusted content to display under the guise of trusted content. This vulnerability affects Firefox < 121.