Mark Sapiro reports:
	  A content injection vulnerability via the options login page has
	    been discovered and reported by Vishal Singh.
	  
	
	  
	    An issue similar to CVE-2018-13796 exists at different endpoint & param. It can lead to a phishing attack.
	  
	
	  
	    (added 2020-05-07) This is essentially the same as
	    https://bugs.launchpad.net/mailman/+bug/1873722 except the vector is
	    the private archive login page and the attack only succeeds if the
	    list's roster visibility (private_roster) setting is 'Anyone'.