Within the <code>lg_init()</code> function, if several allocations succeed but then one fails, an uninitialized pointer would have been freed despite never being allocated. This vulnerability affects Firefox < 102.

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.

The <code>ms-msdt</code>, <code>search</code>, and <code>search-ms</code> protocols deliver content to Microsoft applications, bypassing the browser, when a user accepts a prompt. These applications have had known vulnerabilities, exploited in the wild (although we know of none exploited through Thunderbird), so in this release Thunderbird has blocked these protocols from prompting the user to open them.<br>*This bug only affects Thunderbird on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

The MediaError message property should be consistent to avoid leaking information about cross-origin resources; however for a same-site cross-origin resource, the message could have leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 102.

ASN.1 parsing of an indefinite SEQUENCE inside an indefinite GROUP could have resulted in the parser accepting malformed ASN.1. This vulnerability affects Firefox < 102.

SVG <code>&lt;use&gt;</code> tags that referenced a same-origin document could have resulted in script execution if attacker input was sanitized via the HTML Sanitizer API. This would have required the attacker to reference a same-origin JavaScript file containing the script to be executed. This vulnerability affects Firefox < 102.

Even when an iframe was sandboxed with <code>allow-top-navigation-by-user-activation</code>, if it received a redirect header to an external protocol the browser would process the redirect and prompt the user as appropriate. This vulnerability affects Firefox < 102.

The HTML Sanitizer should have sanitized the <code>href</code> attribute of SVG <code>&lt;use&gt;</code> tags; however it incorrectly did not sanitize <code>xlink:href</code> attributes. This vulnerability affects Firefox < 102.

If there was a PAC URL set and the server that hosts the PAC was not reachable, OCSP requests would have been blocked, resulting in incorrect error pages being shown. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

When downloading an update for an addon, the downloaded addon update's version was not verified to match the version selected from the manifest. If the manifest had been tampered with on the server, an attacker could trick the browser into downgrading the addon to a prior version. This vulnerability affects Firefox < 102.

Session history navigations may have led to a use-after-free and potentially exploitable crash. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

When a TLS Certificate error occurs on a domain protected by the HSTS header, the browser should not allow the user to bypass the certificate error. On Firefox for Android, the user was presented with the option to bypass the error; this could only have been done by the user explicitly. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 102.

An iframe that was not permitted to run scripts could do so if the user clicked on a <code>javascript:</code> link. This vulnerability affects Firefox < 102, Firefox ESR < 91.11, Thunderbird < 102, and Thunderbird < 91.11.

Mozilla developers Gabriele Svelto, Timothy Nikkel, Randell Jesup, Jon Coppeard, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 100. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 101.

Mozilla developers Andrew McCreight, Nicolas B. Pierron, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 100 and Firefox ESR 91.9. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

If array shift operations are not used, the Garbage Collector may have become confused about valid objects. This vulnerability affects Firefox < 101.

An attacker could have injected CSS into stylesheets accessible via internal URIs, such as resource:, and in doing so bypass a page's Content Security Policy. This vulnerability affects Firefox ESR < 91.11, Thunderbird < 102, Thunderbird < 91.11, and Firefox < 101.

Firefox's HTML parser did not correctly interpret HTML comment tags, resulting in an incongruity with other browsers. This could have been used to escape HTML comments on pages that put user-controlled data in them. This vulnerability affects Firefox < 101.

An attacker could have exploited a timing attack by sending a large number of allowCredential entries and detecting the difference between invalid key handles and cross-origin key handles. This could have led to cross-origin account linking in violation of WebAuthn goals. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

A crafted CMS message could have been processed incorrectly, leading to an invalid memory read, and potentially further memory corruption. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.