xml.sax.saxutils.escape and quoteattr incorrectly flagged as insecure

from xml.sax.saxutils import escape
from xml.sax.saxutils import quoteattr

Are flagged as Severity: Low Confidence: High. Instructions are to use the equivalent defusedxml package.

1. I do not believe these imports to be insecure as they are simple text substitutions.
2. There is no defusedxml equivalent.

Expected behavior
Do not mark escape and quoteattr as vulnerable.

Bandit version

bandit 1.5.1
  python version = 3.6.3 (default, Apr 26 2018, 13:16:02) [GCC 4.4.7 20120313 (Red Hat 4.4.7-18)]