CVE-2020-26966

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 83 Firefox ESR versions prior to 78.5 Thunderbird versions prior to 78.5

Description Searching for a single word from the address bar caused an mDNS request to be sent on the local network searching for a hostname consisting of that string, resulting in an information leak. This issue only affected Windows operating systems, while other operating systems are unaffected.

Recommendations For Firefox versions prior to 83, update to version 83 or later. For Firefox ESR versions prior to 78.5, update to version 78.5 or later. For Thunderbird versions prior to 78.5, update to version 78.5 or later.