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 affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.
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 affects Firefox < 140 and Thunderbird < 140.
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 affects Firefox for iOS < 141.
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.
Opening an external link to an HTTP website when Firefox iOS was previously closed and had an HTTPS tab open could in some cases result in the padlock icon showing an HTTPS indicator incorrectly This vulnerability affects Firefox for iOS < 131.2.
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 affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
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 affects Firefox < 136.
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.
Passing invalid data could have led to invalid wasm values being created, such as arbitrary integers turning into pointer values. This vulnerability affects Firefox < 124.
A flaw in handling fullscreen transitions may have inadvertently caused the application to become stuck in fullscreen mode when a modal dialog was opened during the transition. This issue left users unable to exit fullscreen mode using standard actions like pressing "Esc" or accessing right-click menus, resulting in a disrupted browsing experience until the browser is restarted. *This bug only affects the application when running on macOS. Other operating systems are unaffected.* This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.
The executable file warning was not presented when downloading .library-ms files. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.* This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.
When using an invalid protocol scheme, an attacker could spoof the address bar. *Note: This issue only affected Android operating systems. Other operating systems are unaffected.* *Note: This issue is a different issue from CVE-2025-0244. This vulnerability affects Firefox < 134.
Under certain circumstances, a user opt-in setting that Focus should require authentication before use could have been be bypassed. This vulnerability affects Firefox < 134.
A specially crafted filename containing a large number of spaces could obscure the file's extension when displayed in the download dialog. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 131.
Accessing a non-secure HTTP site that uses a non-existent port may cause the SSL padlock icon in the location URL bar to, misleadingly, appear secure. This vulnerability affects Firefox for iOS < 133.
Different techniques existed to obscure the fullscreen notification in Firefox for Android. These could have led to potential user confusion and spoofing attacks. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 126.
Similar to CVE-2023-28163, this time when choosing 'Save Link As', suggested filenames containing environment variable names would have resolved those in the context of the current user. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
A newline in a filename could have been used to bypass the file extension security mechanisms that replace malicious file extensions such as .lnk with .download. This could have led to accidental execution of malicious code. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
A local attacker can trick the Mozilla Maintenance Service into applying an unsigned update file by pointing the service at an update file on a malicious SMB server. The update file can be replaced after the signature check, before the use, because the write-lock requested by the service does not work on a SMB server. *Note: This attack requires local system access and only affects Windows. Other operating systems are not affected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
When recording the screen while in Private Browsing on Firefox for Android the address bar and keyboard were not hidden, potentially leaking sensitive information. *This bug only affects Firefox for Android. Other operating systems are unaffected.* This vulnerability affects Firefox for Android < 112 and Focus for Android < 112.
A compromised child process could have injected XBL Bindings into privileged CSS rules, resulting in arbitrary code execution and a sandbox escape. This vulnerability affects Firefox < 70.
In addition to detecting when a user was taking a screenshot (XXX), a website was able to overlay the 'My Shots' button that appeared, and direct the user to a replica Firefox Screenshots page that could be used for phishing. This vulnerability affects Firefox < 127.
An invalid downcast from `nsHTMLDocument` to `nsIContent` could have lead to undefined behavior. This vulnerability affects Firefox < 110.
If an insecure element was added to a page after a delay, Firefox would not replace the secure icon with a mixed content security status This vulnerability affects Firefox for iOS < 124.
Dragging Javascript URLs to the address bar could cause them to be loaded, bypassing restrictions and security protections This vulnerability affects Firefox for iOS < 124.
The file scheme of URLs would be hidden, resulting in potential spoofing of a website's address in the location bar This vulnerability affects Focus for iOS < 126.
A permissions issue was addressed by removing vulnerable code and adding additional checks. This issue is fixed in iOS 18 and iPadOS 18. Password autofill may fill in passwords after failing authentication.