diff --git a/.github/actions/build-nextjs-website/action.yaml b/.github/actions/build-nextjs-website/action.yaml
index 3f72e40e7..655233b5e 100644
--- a/.github/actions/build-nextjs-website/action.yaml
+++ b/.github/actions/build-nextjs-website/action.yaml
@@ -54,7 +54,7 @@ runs:
   using: "composite"
   steps:
     - name: Download GitBook docs
-      uses: actions/checkout@v4
+      uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
       with:
         repository: pagopa/devportal-docs
         ref: docs/from-gitbook
diff --git a/.github/actions/deploy/action.yaml b/.github/actions/deploy/action.yaml
index a8faf7817..65830de87 100644
--- a/.github/actions/deploy/action.yaml
+++ b/.github/actions/deploy/action.yaml
@@ -74,7 +74,7 @@ runs:
       run: npm run compile
 
     - name: Download GitBook docs
-      uses: actions/checkout@v4
+      uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
       with:
         repository: pagopa/devportal-docs
         ref: docs/from-gitbook
diff --git a/.github/workflows/move_latest_tag.yaml b/.github/workflows/move_latest_tag.yaml
index 67c4d472c..d8f9d3724 100644
--- a/.github/workflows/move_latest_tag.yaml
+++ b/.github/workflows/move_latest_tag.yaml
@@ -11,7 +11,7 @@ jobs:
     if: ${{ startsWith(github.ref, 'refs/tags/') && !endsWith(github.ref, '@latest') }}
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
       
     - name: Get commit hash associated with the new tag
       id: get-commit
diff --git a/apps/chatbot/docker/app.Dockerfile b/apps/chatbot/docker/app.Dockerfile
index 4e2aae36b..ee7f7d3f8 100644
--- a/apps/chatbot/docker/app.Dockerfile
+++ b/apps/chatbot/docker/app.Dockerfile
@@ -1,4 +1,4 @@
-FROM public.ecr.aws/lambda/python:3.12
+FROM public.ecr.aws/lambda/python:3.12@sha256:0a3d34a8310dc339ea7afeb64725df5685da2e6f335dc9287cbc0cddc4a159f2
 ARG DEBIAN_FRONTEND=noninteractive
 
 ENV PYTHONPATH=$LAMBDA_TASK_ROOT
diff --git a/apps/chatbot/docker/app.local.Dockerfile b/apps/chatbot/docker/app.local.Dockerfile
index 21bcd8be8..bfe49f911 100644
--- a/apps/chatbot/docker/app.local.Dockerfile
+++ b/apps/chatbot/docker/app.local.Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.12.4-slim-bullseye
+FROM python:3.12.4-slim-bullseye@sha256:26ce493641ad3b1c8a6202117c31340c7bbb2dc126f1aeee8ea3972730a81dc6
 ARG DEBIAN_FRONTEND=noninteractive
 
 ENV PYTHONPATH=/app