diff --git a/appengine/standard/firebase/firenotes/backend/requirements.txt b/appengine/standard/firebase/firenotes/backend/requirements.txt
index ea3b77a6930..50dc3a1e42a 100644
--- a/appengine/standard/firebase/firenotes/backend/requirements.txt
+++ b/appengine/standard/firebase/firenotes/backend/requirements.txt
@@ -4,3 +4,4 @@ flask-cors==3.0.7
 google-auth==1.6.2
 requests==2.21.0
 requests-toolbelt==0.9.1
+urllib3>=2.6.0 # not directly required, pinned by Snyk to avoid a vulnerability