diff --git a/Misc/NEWS.d/next/Security/2023-10-23-23-37-37.gh-issue-111239.o_q0ef.rst b/Misc/NEWS.d/next/Security/2023-10-23-23-37-37.gh-issue-111239.o_q0ef.rst
new file mode 100644
index 00000000000000..7594725c037e19
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2023-10-23-23-37-37.gh-issue-111239.o_q0ef.rst
@@ -0,0 +1 @@
+Update Windows builds to zlib v1.3. Zlib v1.2.1.3 has CVE-2023-45853.
diff --git a/PCbuild/get_externals.bat b/PCbuild/get_externals.bat
index 94437f054d788c..8e22b7dbe07d07 100644
--- a/PCbuild/get_externals.bat
+++ b/PCbuild/get_externals.bat
@@ -58,7 +58,7 @@ set libraries=%libraries%                                       sqlite-3.43.1.0
 if NOT "%IncludeTkinterSrc%"=="false" set libraries=%libraries% tcl-core-8.6.13.0
 if NOT "%IncludeTkinterSrc%"=="false" set libraries=%libraries% tk-8.6.13.0
 set libraries=%libraries%                                       xz-5.2.5
-set libraries=%libraries%                                       zlib-1.2.13
+set libraries=%libraries%                                       zlib-1.3
 
 for %%e in (%libraries%) do (
     if exist "%EXTERNALS_DIR%\%%e" (
diff --git a/PCbuild/python.props b/PCbuild/python.props
index 496bc3dd4cf794..fa89c856af7318 100644
--- a/PCbuild/python.props
+++ b/PCbuild/python.props
@@ -78,7 +78,7 @@
     <opensslOutDir Condition="$(opensslOutDir) == ''">$(ExternalsDir)openssl-bin-3.0.11\$(ArchName)\</opensslOutDir>
     <opensslIncludeDir Condition="$(opensslIncludeDir) == ''">$(opensslOutDir)include</opensslIncludeDir>
     <nasmDir Condition="$(nasmDir) == ''">$(ExternalsDir)\nasm-2.11.06\</nasmDir>
-    <zlibDir Condition="$(zlibDir) == ''">$(ExternalsDir)\zlib-1.2.13\</zlibDir>
+    <zlibDir Condition="$(zlibDir) == ''">$(ExternalsDir)\zlib-1.3\</zlibDir>
   </PropertyGroup>
 
   <PropertyGroup>