diff --git a/.release-please-bulk-manifest.json b/.release-please-bulk-manifest.json
index 8a7a8474c297..0dd9be7b7858 100644
--- a/.release-please-bulk-manifest.json
+++ b/.release-please-bulk-manifest.json
@@ -17,7 +17,7 @@
   "packages/google-apps-meet": "0.5.0",
   "packages/google-apps-script-type": "0.8.0",
   "packages/google-area120-tables": "0.15.0",
-  "packages/google-auth": "2.56.2",
+  "packages/google-auth": "2.56.3",
   "packages/google-auth-httplib2": "0.4.0",
   "packages/google-auth-oauthlib": "1.4.0",
   "packages/google-backstory": "0.1.0",
diff --git a/librarian.yaml b/librarian.yaml
index 5699ac279a59..0d9a3e74daf5 100644
--- a/librarian.yaml
+++ b/librarian.yaml
@@ -227,7 +227,7 @@ libraries:
       metadata_name_override: area120tables
       default_version: v1alpha1
   - name: google-auth
-    version: 2.56.2
+    version: 2.56.3
     python:
       library_type: AUTH
   - name: google-auth-httplib2
diff --git a/packages/google-auth/CHANGELOG.md b/packages/google-auth/CHANGELOG.md
index 1440d0d8de9e..9149a400f217 100644
--- a/packages/google-auth/CHANGELOG.md
+++ b/packages/google-auth/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-auth/#history
 
+## [2.56.3](https://github.com/googleapis/google-cloud-python/compare/google-auth-v2.56.2...google-auth-v2.56.3) (2026-07-23)
+
+
+### Bug Fixes
+
+* **auth:** avoid creating mTLS SSL context for custom async transports ([#17825](https://github.com/googleapis/google-cloud-python/issues/17825)) ([fbe33f9](https://github.com/googleapis/google-cloud-python/commit/fbe33f9653d61353c0263ac2d0bff71eb76131f8)), closes [#17622](https://github.com/googleapis/google-cloud-python/issues/17622)
+
 ## [2.56.2](https://github.com/googleapis/google-cloud-python/compare/google-auth-v2.56.1...google-auth-v2.56.2) (2026-07-21)
 
 
diff --git a/packages/google-auth/google/auth/version.py b/packages/google-auth/google/auth/version.py
index fe79f2cd138a..d32d0996c684 100644
--- a/packages/google-auth/google/auth/version.py
+++ b/packages/google-auth/google/auth/version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "2.56.2"
+__version__ = "2.56.3"