diff --git a/cmake/host.CMakeLists.txt b/cmake/host.CMakeLists.txt
index c35b8fed0e9..c708eb09eff 100644
--- a/cmake/host.CMakeLists.txt
+++ b/cmake/host.CMakeLists.txt
@@ -131,9 +131,9 @@ set(protobuf_MSVC_STATIC_RUNTIME OFF)
 FetchContent_Declare(
   protobuf
   GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-  GIT_TAG "v23.3"
+  GIT_TAG "v23.4"
   GIT_SUBMODULES ""
-  PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v23.3.patch")
+  PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v23.4.patch")
 FetchContent_MakeAvailable(protobuf)
 list(POP_BACK CMAKE_MESSAGE_INDENT)
 message(CHECK_PASS "fetched")
diff --git a/ortools/dotnet/Google.OrTools-full.csproj.in b/ortools/dotnet/Google.OrTools-full.csproj.in
index 745e2a1648d..e0eba2d4231 100644
--- a/ortools/dotnet/Google.OrTools-full.csproj.in
+++ b/ortools/dotnet/Google.OrTools-full.csproj.in
@@ -176,7 +176,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.23.3"/>
+    <PackageReference Include="Google.Protobuf" Version="3.23.4"/>
   </ItemGroup>
 
   <!-- Need to add required runtime dependencies so Meta-Project will pull runtime Nuget(s) -->
diff --git a/ortools/dotnet/Google.OrTools-local.csproj.in b/ortools/dotnet/Google.OrTools-local.csproj.in
index b1fc83a8180..2a2fb17061c 100644
--- a/ortools/dotnet/Google.OrTools-local.csproj.in
+++ b/ortools/dotnet/Google.OrTools-local.csproj.in
@@ -164,7 +164,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.23.3"/>
+    <PackageReference Include="Google.Protobuf" Version="3.23.4"/>
   </ItemGroup>
 
   <!-- Need to add required runtime dependencies so Meta-Project will pull runtime Nuget(s) -->
diff --git a/ortools/java/pom-full.xml.in b/ortools/java/pom-full.xml.in
index 8f222616039..8c5ff3ab85b 100644
--- a/ortools/java/pom-full.xml.in
+++ b/ortools/java/pom-full.xml.in
@@ -109,7 +109,7 @@
   <dependency>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-java</artifactId>
-    <version>3.23.3</version>
+    <version>3.23.4</version>
   </dependency>
 </dependencies>
 
diff --git a/ortools/java/pom-local.xml.in b/ortools/java/pom-local.xml.in
index 985c3e53640..e644ed98c7f 100644
--- a/ortools/java/pom-local.xml.in
+++ b/ortools/java/pom-local.xml.in
@@ -81,7 +81,7 @@
   <dependency>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-java</artifactId>
-    <version>3.23.3</version>
+    <version>3.23.4</version>
   </dependency>
 </dependencies>
 
diff --git a/ortools/java/pom.xml.in b/ortools/java/pom.xml.in
index 2e417143dcf..17847d3fbda 100644
--- a/ortools/java/pom.xml.in
+++ b/ortools/java/pom.xml.in
@@ -69,7 +69,7 @@
   <dependency>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-java</artifactId>
-    <version>3.23.3</version>
+    <version>3.23.4</version>
   </dependency>
   <dependency>
     <groupId>junit</groupId>
diff --git a/ortools/python/setup.py.in b/ortools/python/setup.py.in
index 2de5e4d232b..6912c0fc625 100644
--- a/ortools/python/setup.py.in
+++ b/ortools/python/setup.py.in
@@ -45,7 +45,7 @@ setup(
     install_requires=[
         'absl-py >= 0.13',
         'numpy >= 1.13.3',
-        'protobuf >= 4.23.3',
+        'protobuf >= 4.23.4',
     ],
     package_data={
         '@PYTHON_PROJECT@':[$<$<STREQUAL:$<TARGET_PROPERTY:@PROJECT_NAME@,TYPE>,SHARED_LIBRARY>:'.libs/*','../$<TARGET_SONAME_FILE_NAME:@PROJECT_NAME@>'>],
diff --git a/patches/BUILD.bazel b/patches/BUILD.bazel
index faa18853741..c46a362dbd7 100644
--- a/patches/BUILD.bazel
+++ b/patches/BUILD.bazel
@@ -12,7 +12,7 @@
 # limitations under the License.
 
 exports_files([
-    "protobuf-v23.3.patch",
+    "protobuf-v23.4.patch",
     "pybind11_bazel.patch",
     "pybind11_protobuf.patch",
 ])