diff --git a/comanage-registry-base/Dockerfile b/comanage-registry-base/Dockerfile
index 2f0bc64..20d5c91 100644
--- a/comanage-registry-base/Dockerfile
+++ b/comanage-registry-base/Dockerfile
@@ -16,7 +16,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-FROM php:7.3.27-apache-buster
+FROM php:7.3.28-apache-buster
 
 # Official PHP image with Apache HTTPD includes
 # --with-openssl
diff --git a/comanage-registry-internet2-tier-base/Dockerfile b/comanage-registry-internet2-tier-base/Dockerfile
index fa21db3..bb931c3 100644
--- a/comanage-registry-internet2-tier-base/Dockerfile
+++ b/comanage-registry-internet2-tier-base/Dockerfile
@@ -20,7 +20,7 @@ FROM centos/python-38-centos7 AS php-build
 
 USER root
 
-ARG PHP_VERSION=7.3.27
+ARG PHP_VERSION=7.3.28
 ARG PHP_SRC_URL=https://github.com/php/php-src/archive/php-${PHP_VERSION}.tar.gz
 
 RUN yum -y install epel-release \