diff --git a/.github/workflows/main/installDependencies.py b/.github/workflows/main/installDependencies.py
index a2ac3737e92..52b69e46bc2 100755
--- a/.github/workflows/main/installDependencies.py
+++ b/.github/workflows/main/installDependencies.py
@@ -48,7 +48,7 @@
 
 # Determine default archive URL.
 
-defaultURL = "https://github.com/ImageEngine/cortex/releases/download/10.5.4.0/cortex-10.5.4.0-{platform}-python3.{extension}".format(
+defaultURL = "https://github.com/ImageEngine/cortex/releases/download/10.5.4.2/cortex-10.5.4.2-{platform}-python3.{extension}".format(
 	platform = { "darwin" : "osx", "win32" : "windows" }.get( sys.platform, "linux" ),
 	extension = "tar.gz" if sys.platform != "win32" else "zip"
 )
diff --git a/Changes.md b/Changes.md
index 4f653240f44..a81e95b7731 100644
--- a/Changes.md
+++ b/Changes.md
@@ -30,6 +30,8 @@ Fixes
   - Fixed translation of `UsdPreviewSurface` normal maps.
   - Fixed translation of `UsdPreviewSurface` `specularColor` fallback value.
 - Scene History : Fixed error caused by `Alt+E` keypress on panels other than the Viewer, HierarchyView, LightEditor or NodeEditor.
+- ImageReader : Fixed crashes caused by null `ustring` metadata values.
+- Exception handling : Fixed memory leak caused by translation of `IECore::Exception` from C++ to Python and back again.
 
 API
 ---
@@ -43,6 +45,7 @@ API
 Build
 -----
 
+- Cortex : Updated to version 10.5.4.2.
 - Instancer : Fixed ambiguous reference compilation errors when building with Boost 1.70.
 
 1.3.7.0 (relative to 1.3.6.1)