CVE-2020-6798

If a template tag was used in a select tag, the parser could be confused
and allow JavaScript parsing and execution when it should not be allowed. A
site that relied on the browser behaving correctly could suffer a
cross-site scripting vulnerability as a result. In general, this flaw
cannot be exploited through email in the Thunderbird product because
scripting is disabled when reading mail, but is potentially a risk in
browser or browser-like contexts. This vulnerability affects Thunderbird <
68.5, Firefox < 73, and Firefox < ESR68.5.

Notes