diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 10fba78..bc6036e 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -9,7 +9,7 @@ updates:
       - "dependencies"
       - "php"
     cooldown:
-      default-days: 5
+      default-days: 7
       semver-major-days: 7
       semver-minor-days: 5
       semver-patch-days: 3
@@ -23,4 +23,4 @@ updates:
       - "dependencies"
       - "github-actions"
     cooldown:
-      default-days: 5
+      default-days: 7
diff --git a/.github/workflows/fix-style.yml b/.github/workflows/fix-style.yml
index 795a081..7f5fd51 100644
--- a/.github/workflows/fix-style.yml
+++ b/.github/workflows/fix-style.yml
@@ -37,7 +37,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index 5317cc2..640cccc 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -35,7 +35,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 68a470e..2629b40 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -41,7 +41,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
@@ -77,7 +77,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
diff --git a/.github/workflows/zizmor.yml b/.github/workflows/zizmor.yml
new file mode 100644
index 0000000..fca122e
--- /dev/null
+++ b/.github/workflows/zizmor.yml
@@ -0,0 +1,44 @@
+name: "Audit GitHub Actions"
+
+on:
+  push:
+    branches:
+      - main
+      - master
+    paths:
+      - '.github/workflows/**'
+  pull_request:
+    branches:
+      - main
+      - master
+    paths:
+      - '.github/workflows/**'
+  schedule:
+    - cron: '17 6 * * 1'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  zizmor:
+    name: "Zizmor GitHub Actions Audit"
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Audit GitHub Actions workflows
+        uses: zizmorcore/zizmor-action@3dc1ecc9bcb9e94e9b2c709687979e1298497054 # v0.6.2
+        with:
+          advanced-security: false
+          annotations: true
+          version: 1.29.0
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3da18b9..46f5751 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Security
 
 - Pinned all third-party GitHub Actions to immutable full commit SHAs.
+- Added a blocking, SHA-pinned Zizmor workflow audit with a fixed scanner
+  version for deterministic GitHub Actions security checks.
 - Added Dependabot cooldowns of at least three days for Composer and GitHub
   Actions updates to reduce exposure to newly compromised releases.
 - Restricted GitHub Actions tokens to read-only repository contents and stopped