CVE 2020-8287
Node.js versions before 10.23.1, 12.20.1, 14.15.4, 15.5.1 allow two copies of a header field in an HTTP request (for example, two Transfer-Encoding header fields). In this case, Node.js identifies the first header field and ignores the second. This can lead to HTTP Request Smuggling.
See the 
CVE page on Mitre.org
for more details.
