diff --git a/.github/workflows/brakeman-scan-core.yml b/.github/workflows/brakeman-scan-core.yml
index 25cce7f6fb..3722bf183f 100644
--- a/.github/workflows/brakeman-scan-core.yml
+++ b/.github/workflows/brakeman-scan-core.yml
@@ -10,8 +10,14 @@ on:
   schedule:
     - cron: '10 6 * * 1'
 
+permissions:
+  contents: read
+
 jobs:
   brakeman-scan:
+    permissions:
+      contents: read  # for actions/checkout to fetch code
+      security-events: write  # for github/codeql-action/upload-sarif to upload SARIF results
     if: github.repository == 'opf/openproject'
     name: Brakeman Scan
     runs-on: ubuntu-latest
diff --git a/.github/workflows/continuous-delivery.yml b/.github/workflows/continuous-delivery.yml
index f0fe5b441f..06dc824b03 100644
--- a/.github/workflows/continuous-delivery.yml
+++ b/.github/workflows/continuous-delivery.yml
@@ -4,8 +4,13 @@ on:
     branches:
       - dev
       - release/*
+permissions:
+  contents: read
+
 jobs:
   trigger_downstream_workflow:
+    permissions:
+      contents: none
     if: github.repository == 'opf/openproject'
     runs-on: ubuntu-latest
     steps:
diff --git a/.github/workflows/test-core.yml b/.github/workflows/test-core.yml
index b86148a369..59044c7163 100644
--- a/.github/workflows/test-core.yml
+++ b/.github/workflows/test-core.yml
@@ -14,6 +14,9 @@ on:
       - 'docs/**'
       - 'help/**'
 
+permissions:
+  contents: read
+
 jobs:
   units:
     name: Units