diff --git a/Gemfile b/Gemfile
index 7bb8e5e5f20c48f1783c34cf9b77f120d7368122..53cb8905cca4347eee940f472740bce9acfc86b1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -210,7 +210,7 @@ gem 'diffy', '~> 3.4'
 gem 'diff_match_patch', '~> 0.1.0'
 
 # Application server
-gem 'rack', '~> 2.2.6', '>= 2.2.6.2'
+gem 'rack', '~> 2.2.6', '>= 2.2.6.4'
 # https://github.com/zombocom/rack-timeout/blob/master/README.md#rails-apps-manually
 gem 'rack-timeout', '~> 0.6.3', require: 'rack/timeout/base'
 
diff --git a/Gemfile.checksum b/Gemfile.checksum
index 4fce46bbafa1e6b6c6f9094f693c75be401bad3e..d027ba033796dd56e990f2703d8a44649803e32c 100644
--- a/Gemfile.checksum
+++ b/Gemfile.checksum
@@ -456,7 +456,7 @@
 {"name":"raabro","version":"1.4.0","platform":"ruby","checksum":"d4fa9ff5172391edb92b242eed8be802d1934b1464061ae5e70d80962c5da882"},
 {"name":"racc","version":"1.6.2","platform":"java","checksum":"0880781e7dfde09e665d0b6160b583e01ed52fcc2955d7891447d33c2d1d2cf1"},
 {"name":"racc","version":"1.6.2","platform":"ruby","checksum":"58d26b3666382396fea84d33dc0639b7ee8d704156a52f8f22681f07b2f94f26"},
-{"name":"rack","version":"2.2.6.2","platform":"ruby","checksum":"4be320c0fdea6651f0247dbd4182c1bd8acc06606a6b8935a19ad6a504347763"},
+{"name":"rack","version":"2.2.6.4","platform":"ruby","checksum":"d3d92be402b5881058caccc0975e6d67a1e0ba929d1d144a43daf689169bfce1"},
 {"name":"rack-accept","version":"0.4.5","platform":"ruby","checksum":"66247b5449db64ebb93ae2ec4af4764b87d1ae8a7463c7c68893ac13fa8d4da2"},
 {"name":"rack-attack","version":"6.6.1","platform":"ruby","checksum":"187e5d248c6a162ed8cafa8241a7b5947d9b9cf122a4870eb1cdd0db861f3a11"},
 {"name":"rack-cors","version":"1.1.1","platform":"ruby","checksum":"4702644ac6d63ebbddff372a3cd4cd573513287e3524b5a5415f678970057a4b"},
diff --git a/Gemfile.lock b/Gemfile.lock
index 7e53437a0bb05de5a6cde9af332bea6a1c82a93e..08a399175d1f27b5056892741199f01667053ac6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1151,7 +1151,7 @@ GEM
     pyu-ruby-sasl (0.0.3.3)
     raabro (1.4.0)
     racc (1.6.2)
-    rack (2.2.6.2)
+    rack (2.2.6.4)
     rack-accept (0.4.5)
       rack (>= 0.4)
     rack-attack (6.6.1)
@@ -1842,7 +1842,7 @@ DEPENDENCIES
   pry-shell (~> 0.6.1)
   puma (~> 5.6.5)
   puma_worker_killer (~> 0.3.1)
-  rack (~> 2.2.6, >= 2.2.6.2)
+  rack (~> 2.2.6, >= 2.2.6.4)
   rack-attack (~> 6.6.1)
   rack-cors (~> 1.1.1)
   rack-oauth2 (~> 1.21.3)