diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 22d617f..eebc971 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -18,20 +18,22 @@ jobs:
       security-events: write
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
 
       - name: Free disk space
         run: sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc /opt/hostedtoolcache/go
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.39.0
+        uses: github/codeql-action/init@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
         with:
           languages: python
 
       - name: Autobuild
-        uses: github/codeql-action/autobuild@v4.39.0
+        uses: github/codeql-action/autobuild@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.39.0
+        uses: github/codeql-action/analyze@6f2ac81f5cd81fe351a197ba0b00d91d03cd2aee # v4.39.0
         with:
           category: "/language:python"
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 7763b0f..dbf86b8 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -13,14 +13,16 @@ jobs:
       id-token: write  # required for OIDC trusted publishing
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
 
-      - uses: actions/setup-python@v7
+      - uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7
         with:
           python-version: "3.12"
 
       - name: Install Poetry
-        uses: snok/install-poetry@v1
+        uses: snok/install-poetry@a783c322200f0519c7926aa6faa857c4e23e9263 # v1
         with:
           version: 2.4.1
           virtualenvs-create: true
@@ -30,7 +32,7 @@ jobs:
         run: poetry install --no-interaction --no-root --only main
 
       - name: Audit dependencies
-        uses: pypa/gh-action-pip-audit@v1.1.0
+        uses: pypa/gh-action-pip-audit@1220774d901786e6f652ae159f7b6bc8fea6d266 # v1.1.0
         with:
           virtual-environment: .venv
 
@@ -41,4 +43,4 @@ jobs:
         run: python -m build
 
       - name: Publish to PyPI
-        uses: pypa/gh-action-pypi-publish@release/v1
+        uses: pypa/gh-action-pypi-publish@7245906fb61fa33a13554f9d5fb856fe61758086 # release/v1
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
index 70bd8b3..991e363 100644
--- a/.github/workflows/security.yml
+++ b/.github/workflows/security.yml
@@ -8,21 +8,26 @@ on:
   schedule:
     - cron: "0 6 * * 1"
 
+permissions:
+  contents: read
+
 jobs:
   pip-audit:
     name: Dependency Vulnerability Scan
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
 
       - name: Set up Python
-        uses: actions/setup-python@v7
+        uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7
         with:
           python-version: "3.12"
 
       - name: Install Poetry
-        uses: snok/install-poetry@v1
+        uses: snok/install-poetry@a783c322200f0519c7926aa6faa857c4e23e9263 # v1
         with:
           version: 2.4.1
           virtualenvs-create: true
@@ -30,7 +35,7 @@ jobs:
 
       - name: Load cached venv
         id: cached-poetry-dependencies
-        uses: actions/cache@v6
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
         with:
           path: .venv
           key: venv-security-${{ runner.os }}-3.12-${{ hashFiles('**/poetry.lock') }}
@@ -40,6 +45,6 @@ jobs:
         run: poetry install --no-interaction --no-root
 
       - name: Audit dependencies
-        uses: pypa/gh-action-pip-audit@v1.1.0
+        uses: pypa/gh-action-pip-audit@1220774d901786e6f652ae159f7b6bc8fea6d266 # v1.1.0
         with:
           virtual-environment: .venv
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 5fdb5cd..d16e265 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -6,6 +6,9 @@ on:
   pull_request:
     branches: [main]
 
+permissions:
+  contents: read
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -14,15 +17,17 @@ jobs:
         python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v7
+        uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7
         with:
           python-version: ${{ matrix.python-version }}
 
       - name: Install Poetry
-        uses: snok/install-poetry@v1
+        uses: snok/install-poetry@a783c322200f0519c7926aa6faa857c4e23e9263 # v1
         with:
           version: 2.4.1
           virtualenvs-create: true
@@ -30,7 +35,7 @@ jobs:
 
       - name: Load cached venv
         id: cached-poetry-dependencies
-        uses: actions/cache@v6
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
         with:
           path: .venv
           key: venv-${{ runner.os }}-${{ matrix.python-version }}-${{ hashFiles('**/poetry.lock') }}
@@ -57,17 +62,19 @@ jobs:
         django-version: ["4.2", "5.2", "6.0", "6.1"]
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
 
       - name: Set up Python
-        uses: actions/setup-python@v7
+        uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7
         with:
           # 3.12 is the one Python version every entry in the matrix supports:
           # Django 4.2 added 3.12 support in 4.2.8; Django 6.0/6.1 require 3.12+.
           python-version: "3.12"
 
       - name: Install Poetry
-        uses: snok/install-poetry@v1
+        uses: snok/install-poetry@a783c322200f0519c7926aa6faa857c4e23e9263 # v1
         with:
           version: 2.4.1
           virtualenvs-create: true
@@ -86,15 +93,17 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
 
       - name: Set up Python
-        uses: actions/setup-python@v7
+        uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7
         with:
           python-version: "3.14"
 
       - name: Install Poetry
-        uses: snok/install-poetry@v1
+        uses: snok/install-poetry@a783c322200f0519c7926aa6faa857c4e23e9263 # v1
         with:
           version: 2.4.1
           virtualenvs-create: true