Mozilla Thunderbird is a standalone mail and newsgroup client. This update upgrades Thunderbird to version 91.6.0. Security Fix: * Mozilla: Extensions could have bypassed permission confirmation during update * Mozilla: Memory safety bugs fixed in Firefox 97 and Firefox ESR 91.6 * Mozilla: Drag and dropping an image could have resulted in the dropped object being an executable * Mozilla: Sandboxed iframes could have executed script if the parent appended elements * Mozilla: Cross-Origin responses could be distinguished between script and non-script content-types * Mozilla: frame-ancestors Content Security Policy directive was not enforced for framed extension pages * Mozilla: Script Execution during invalid object state For more details about the security issue, including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page listed in the References section.