diff --git a/Lib/difflib.py b/Lib/difflib.py
index 887c3c26cae..4571817b982 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -2036,6 +2036,10 @@ class HtmlDiff(object):
s.append( fmt % (next_id[i],next_href[i],fromlist[i],
next_href[i],tolist[i]))
if fromdesc or todesc:
+ fromdesc = fromdesc.replace("&", "&").replace(">", ">") \
+ .replace("<", "<")
+ todesc = todesc.replace("&", "&").replace(">", ">") \
+ .replace("<", "<")
header_row = '%s%s%s%s
' % (
'
| ',
'' % fromdesc,
diff --git a/Lib/test/test_difflib.py b/Lib/test/test_difflib.py
index 745ccbd6659..63ebdb0dc83 100644
--- a/Lib/test/test_difflib.py
+++ b/Lib/test/test_difflib.py
@@ -238,6 +238,15 @@ class TestSFpatches(unittest.TestCase):
with open(findfile('test_difflib_expect.html')) as fp:
self.assertEqual(actual, fp.read())
+ def test_make_table_escape_table_header(self):
+ html_diff = difflib.HtmlDiff()
+ output = html_diff.make_table(patch914575_from1.splitlines(),
+ patch914575_to1.splitlines(),
+ fromdesc='',
+ todesc='')
+ self.assertIn('<from>', output)
+ self.assertIn('<to>', output)
+
def test_recursion_limit(self):
# Check if the problem described in patch #1413711 exists.
limit = sys.getrecursionlimit()
diff --git a/Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst b/Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst
new file mode 100644
index 00000000000..03150c3aa49
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-12-28-14-53-22.bpo-35603.rVCZAE.rst
@@ -0,0 +1,2 @@
+Escape table header output of :meth:`difflib.HtmlDiff.make_table`.
+Patch by Karthikeyan Singaravelan.