CVE-2020-26961

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 The issue arises when DNS over HTTPS is in use, and it fails to filter out RFC1918 and related IP ranges from responses when an IPv4 address is mapped through IPv6. This oversight can lead to a potential DNS Rebinding attack.

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