diff --git a/Dependencies.txt b/Dependencies.txt
index 89f8de23c6..aa2486ca7c 100644
--- a/Dependencies.txt
+++ b/Dependencies.txt
@@ -1,4 +1,4 @@
-Protobuf=3.15.7
+Protobuf=3.15.8
 abseil-cpp=20210324.1
 Cbc=2.10.5
 Cgl=0.60.3
diff --git a/WORKSPACE b/WORKSPACE
index ac4fa14cf4..e4c2218b8a 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -29,7 +29,7 @@ http_archive(
 # Protobuf
 git_repository(
     name = "com_google_protobuf",
-    commit = "878be35",  # release v3.15.7
+    commit = "436bd78",  # release v3.15.8
     remote = "https://github.com/protocolbuffers/protobuf.git",
 )
 
diff --git a/cmake/dependencies/CMakeLists.txt b/cmake/dependencies/CMakeLists.txt
index 17f222732c..b545818ce2 100644
--- a/cmake/dependencies/CMakeLists.txt
+++ b/cmake/dependencies/CMakeLists.txt
@@ -114,17 +114,17 @@ if(BUILD_Protobuf)
     FetchContent_Declare(
       protobuf
       GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-      GIT_TAG "v3.15.7"
+      GIT_TAG "v3.15.8"
       GIT_SUBMODULES ""
-      PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v3.15.7.patch"
+      PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v3.15.8.patch"
       SOURCE_SUBDIR cmake)
     FetchContent_MakeAvailable(protobuf)
   else()
     fetch_git_dependency(
       NAME Protobuf
       REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-      TAG "v3.15.7"
-      PATCH_COMMAND "git apply \"${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v3.15.7.patch\""
+      TAG "v3.15.8"
+      PATCH_COMMAND "git apply \"${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v3.15.8.patch\""
       SOURCE_SUBDIR cmake
       )
   endif()
diff --git a/cmake/host.CMakeLists.txt b/cmake/host.CMakeLists.txt
index c3b770c405..05d26bc023 100644
--- a/cmake/host.CMakeLists.txt
+++ b/cmake/host.CMakeLists.txt
@@ -106,17 +106,17 @@ if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.18")
   FetchContent_Declare(
       protobuf
       GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-      GIT_TAG "v3.15.7"
+      GIT_TAG "v3.15.8"
       GIT_SUBMODULES ""
-      PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v3.15.7.patch"
+      PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v3.15.8.patch"
       SOURCE_SUBDIR cmake)
   FetchContent_MakeAvailable(protobuf)
 else()
   fetch_git_dependency(
       NAME Protobuf
       REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-      TAG "v3.15.7"
-      PATCH_COMMAND "git apply \"${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v3.15.7.patch\""
+      TAG "v3.15.8"
+      PATCH_COMMAND "git apply \"${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v3.15.8.patch\""
       SOURCE_SUBDIR cmake)
 endif()
 list(POP_BACK CMAKE_MESSAGE_INDENT)
diff --git a/makefiles/Makefile.third_party.unix.mk b/makefiles/Makefile.third_party.unix.mk
index ccf59b5d7a..9fdbef3772 100644
--- a/makefiles/Makefile.third_party.unix.mk
+++ b/makefiles/Makefile.third_party.unix.mk
@@ -20,7 +20,7 @@ UNIX_SWIG_BINARY ?= swig
 PROTOC_BINARY := $(shell $(WHICH) ${UNIX_PROTOC_BINARY})
 
 # Tags of dependencies to checkout.
-PROTOBUF_TAG = v3.15.7
+PROTOBUF_TAG = v3.15.8
 ABSL_TAG = 20210324.1
 CBC_TAG = 2.10.5
 CGL_TAG = 0.60.3
diff --git a/makefiles/Makefile.third_party.win.mk b/makefiles/Makefile.third_party.win.mk
index f473da5e4e..cbb06bca7f 100644
--- a/makefiles/Makefile.third_party.win.mk
+++ b/makefiles/Makefile.third_party.win.mk
@@ -35,7 +35,7 @@ SWIG_BINARY = $(WINDOWS_SWIG_BINARY)
 # tags of dependencies to checkout.
 ZLIB_TAG = 1.2.11
 ZLIB_ARCHIVE_TAG = 1211
-PROTOBUF_TAG = v3.15.7
+PROTOBUF_TAG = v3.15.8
 ABSL_TAG = 20210324.1
 # We are using a CBC archive containing all coin-or project
 # since Clp 2.17.5+ is broken we need to stick with Cbc 2.10.4
diff --git a/ortools/dotnet/Google.OrTools/Google.OrTools.csproj.in b/ortools/dotnet/Google.OrTools/Google.OrTools.csproj.in
index bcb42535ec..d7cb13b971 100644
--- a/ortools/dotnet/Google.OrTools/Google.OrTools.csproj.in
+++ b/ortools/dotnet/Google.OrTools/Google.OrTools.csproj.in
@@ -141,7 +141,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.15.7"/>
+    <PackageReference Include="Google.Protobuf" Version="3.15.8"/>
   </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 6a2a3befbc..d9f67aadc4 100644
--- a/ortools/java/pom-full.xml.in
+++ b/ortools/java/pom-full.xml.in
@@ -95,7 +95,7 @@
   <dependency>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-java</artifactId>
-    <version>3.15.7</version>
+    <version>3.15.8</version>
   </dependency>
 </dependencies>
 
diff --git a/ortools/java/pom-local.xml.in b/ortools/java/pom-local.xml.in
index 7d0d5c5f5e..1ffc1408b1 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>3.15.7</version>
+    <version>3.15.8</version>
   </dependency>
 </dependencies>
 
diff --git a/ortools/java/pom.xml.in b/ortools/java/pom.xml.in
index 3aeb6b4b74..056db54f02 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>3.15.7</version>
+    <version>3.15.8</version>
   </dependency>
   <dependency>
     <groupId>junit</groupId>
diff --git a/ortools/python/setup.py.in b/ortools/python/setup.py.in
index 2fcf1611c7..4a61fec978 100644
--- a/ortools/python/setup.py.in
+++ b/ortools/python/setup.py.in
@@ -42,7 +42,7 @@ setup(
     version='@PROJECT_VERSION@',
     packages=find_packages(),
     install_requires=[
-        'protobuf >= 3.15.7',
+        'protobuf >= 3.15.8',
         'absl-py >= 0.11',
     ],
     package_data={
diff --git a/patches/protobuf-v3.15.7.patch b/patches/protobuf-v3.15.8.patch
similarity index 100%
rename from patches/protobuf-v3.15.7.patch
rename to patches/protobuf-v3.15.8.patch
diff --git a/tools/setup.py.in b/tools/setup.py.in
index 1be0724676..2c23707245 100644
--- a/tools/setup.py.in
+++ b/tools/setup.py.in
@@ -42,7 +42,7 @@ setup(
     version='VVVV',
     packages=find_packages(),
     install_requires=[
-        'protobuf >= 3.15.7',
+        'protobuf >= 3.15.8',
         'absl-py >= 0.11',
     ],
     package_data={