diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 59bd0e26..e98d3e58 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -58,7 +58,7 @@ jobs:
         restore-keys: bazel-disk-arenastring-${{matrix.compiler.name}}-${{matrix.stdlib.name}}-${{matrix.mutable.name}}-
         save-always: true
     - run: sudo apt install libc++-18-dev libc++abi-18-dev
-    - run: sed -i "/single_version_override.*protobuf/s/version = '[^']*'/version = '27.3.arenastring'/" MODULE.bazel
+    - run: sed -i "/single_version_override.*protobuf/s/version = '[^']*'/version = '27.5.arenastring'/" MODULE.bazel
     - run: bazel test --compilation_mode=opt --disk_cache=bazel-disk --verbose_failures --test_output=errors --config=asan ${{matrix.compiler.flag}} ${{matrix.stdlib.flag}} ${{matrix.mutable.flag}} test/...
 
   aarch64:
diff --git a/MODULE.bazel b/MODULE.bazel
index 07b40bef..a0f7b572 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -25,7 +25,7 @@ bazel_dep(name = 'boost.spirit', version = '1.83.0.bzl.2')
 
 # --registry=https://bcr.bazel.build
 single_version_override(module_name = 'abseil-cpp', version = '20240722.0')
-single_version_override(module_name = 'protobuf', version = '27.3')
+single_version_override(module_name = 'protobuf', version = '27.5')
 bazel_dep(name = 'googletest', version = '1.15.2', repo_name = 'com_google_googletest', dev_dependency = True)
 bazel_dep(name = 'platforms', version = '0.0.10', dev_dependency = True)
 bazel_dep(name = 'rules_cc', version = '0.0.9', dev_dependency = True)
diff --git a/registry/modules/protobuf/25.3/source.json b/registry/modules/protobuf/25.3/source.json
deleted file mode 100644
index 8730c44f..00000000
--- a/registry/modules/protobuf/25.3/source.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-  "url": "https://github.com/protocolbuffers/protobuf/archive/refs/tags/v25.3.tar.gz",
-  "strip_prefix": "protobuf-25.3",
-  "integrity": "sha256-0ZZD0mW5eDgzUrMUPwTAZB7qdadSNcERzAGhNQFzGA4="
-}
diff --git a/registry/modules/protobuf/25.3/MODULE.bazel b/registry/modules/protobuf/27.5.arenastring/MODULE.bazel
similarity index 50%
rename from registry/modules/protobuf/25.3/MODULE.bazel
rename to registry/modules/protobuf/27.5.arenastring/MODULE.bazel
index 7770704e..f1f2a0c9 100644
--- a/registry/modules/protobuf/25.3/MODULE.bazel
+++ b/registry/modules/protobuf/27.5.arenastring/MODULE.bazel
@@ -1,7 +1,10 @@
+# TODO: migrate all dependencies from WORKSPACE to MODULE.bazel
+# https://github.com/protocolbuffers/protobuf/issues/14313
 module(
     name = "protobuf",
-    version = "25.3",
+    version = "27.5.arenastring", # Automatically updated on release
     compatibility_level = 1,
+    repo_name = "com_google_protobuf",
 )
 
 # LOWER BOUND dependency versions.
@@ -12,7 +15,7 @@ bazel_dep(name = "abseil-cpp", version = "20230802.0.bcr.1", repo_name = "com_go
 bazel_dep(name = "bazel_skylib", version = "1.4.1")
 bazel_dep(name = "jsoncpp", version = "1.9.5")
 bazel_dep(name = "rules_cc", version = "0.0.9")
-bazel_dep(name = "rules_java", version = "4.0.0")
+bazel_dep(name = "rules_java", version = "5.3.5")
 bazel_dep(name = "rules_jvm_external", version = "5.1")
 bazel_dep(name = "rules_pkg", version = "0.7.0")
 bazel_dep(name = "rules_python", version = "0.10.2")
@@ -22,5 +25,13 @@ bazel_dep(name = "zlib", version = "1.2.11")
 # TODO: remove after toolchain types are moved to protobuf
 bazel_dep(name = "rules_proto", version = "4.0.0")
 
-bazel_dep(name = "rules_ruby", version = "protobuf-25.3")
-bazel_dep(name = "utf8_range", version = "protobuf-25.3")
+bazel_dep(name = "googletest", version = "1.14.0", repo_name = "com_google_googletest", dev_dependency = True)
+bazel_dep(name = "rules_ruby", dev_dependency = True)
+archive_override(
+    module_name = "rules_ruby",
+    urls = ["https://github.com/protocolbuffers/rules_ruby/archive/b7f3e9756f3c45527be27bc38840d5a1ba690436.tar.gz"],
+    strip_prefix = "rules_ruby-b7f3e9756f3c45527be27bc38840d5a1ba690436",
+    integrity = "sha256-RNo21X/p9slOdF912FLprLnxvZHMXBTxaUDGFmm2bx8=",
+    patches = ["third_party/rules_ruby.patch"],
+    patch_strip = 1,
+)
diff --git a/registry/modules/protobuf/27.5.arenastring/patches/arenastring.patch b/registry/modules/protobuf/27.5.arenastring/patches/arenastring.patch
new file mode 100644
index 00000000..e69de29b
diff --git a/registry/modules/protobuf/27.5.arenastring/source.json b/registry/modules/protobuf/27.5.arenastring/source.json
new file mode 100644
index 00000000..009ffad0
--- /dev/null
+++ b/registry/modules/protobuf/27.5.arenastring/source.json
@@ -0,0 +1,9 @@
+{
+  "url": "https://github.com/protocolbuffers/protobuf/releases/download/v27.5/protobuf-27.5.zip",
+  "strip_prefix": "protobuf-27.5",
+  "integrity": "sha256-6e/2D/bIBiAV3R0gGnVWuWX0q+bLbyjL6vjmiPih3BU=",
+  "patch_strip": 1,
+  "patches": {
+    "arenastring.patch": "sha256-47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU"
+  }
+}