Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Loofah < 2.19.1 contains an inefficient regular expression that is susceptible to excessive backtracking when attempting to sanitize certain SVG attributes. This may lead to a denial of service through CPU resource consumption. This issue is patched in version 2.19.1.
https://lists.debian.org/debian-lts-announce/2023/09/msg00011.html
https://hackerone.com/reports/1684163
https://github.com/flavorjones/loofah/security/advisories/GHSA-486f-hjj9-9vhh