Bad validation logic in the Dart SDK versions prior to 2.12.3 allow an attacker to use an XSS attack via DOM clobbering. The validation logic in dart:html for creating DOM nodes from text did not sanitize properly when it came across template tags.
{ "versions": [ { "introduced": "0" }, { "fixed": "2.12.3" } ] }
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-22540.json"