The attachment scrubber (Scrubber.py) in Mailman 2.1.5 and earlier, when using Python's library email module 2.5, allows remote attackers to cause a denial of service (mailing list delivery failure) via a multipart MIME message with a single part that has two blank lines between the first boundary and the end boundary.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.064
EPSS Ranking 90.5%