diff --git a/requirements.txt b/requirements.txt
index f6c71df..8875205 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -119,7 +119,7 @@ stix2==3.0.1
 stix2-patterns==2.0.0
 terminado==0.18.1
 tinycss2==1.2.1
-tornado==6.5.1
+tornado==6.5.5
 traitlets==5.14.2
 twine==5.0.0
 types-python-dateutil==2.9.0.20240316