diff --git a/cuckoo/requirements.txt b/cuckoo/requirements.txt
index 047df10..f81e0e2 100644
--- a/cuckoo/requirements.txt
+++ b/cuckoo/requirements.txt
@@ -15,7 +15,7 @@ ipaddress==1.0.14
 itsdangerous==0.24
 Jinja2==2.8
 jsbeautifier==1.5.10
-lxml==3.6.0
+lxml==4.9.1
 Mako==1.0.1
 MarkupSafe==0.23
 ndg-httpsclient==0.4.0