diff --git a/.github/actions/checkout/action.yml b/.github/actions/checkout/action.yml
index ab8c663e0f0e..60171fee28d4 100644
--- a/.github/actions/checkout/action.yml
+++ b/.github/actions/checkout/action.yml
@@ -15,7 +15,7 @@ runs:
   steps:
     # We don't actually need anything in this directory, but we need a small
     # sparse checkout, and this directory is small.
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       with:
         persist-credentials: false
         sparse-checkout: .github/actions
diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index 6df5e18009fa..e2ea3d07142c 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -36,13 +36,16 @@ jobs:
           permission-pull-requests: write
           permission-workflows: write
 
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           # Avoid materializing full nixpkgs tree
           sparse-checkout: .
           token: ${{ steps.app-token.outputs.token }}
           persist-credentials: true
+          # The PR is already merged, and its commits are only cherry-picked by
+          # git, never executed, so checking out fork PR commits is safe here.
+          allow-unsafe-pr-checkout: true
 
       - name: Log current API rate limits
         env:
diff --git a/.github/workflows/bot.yml b/.github/workflows/bot.yml
index 3e404d89c8c2..d47bcc942131 100644
--- a/.github/workflows/bot.yml
+++ b/.github/workflows/bot.yml
@@ -42,7 +42,7 @@ jobs:
     runs-on: ubuntu-slim
     if: github.event_name != 'schedule' || github.repository_owner == 'NixOS'
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout: |
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 84c34887b7f3..06f9fa8d8e90 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -47,7 +47,7 @@ jobs:
     runs-on: ubuntu-slim
     timeout-minutes: 3
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           path: trusted
@@ -101,7 +101,7 @@ jobs:
     runs-on: ubuntu-24.04-arm
     timeout-minutes: 8
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           path: trusted
@@ -147,7 +147,7 @@ jobs:
     runs-on: ubuntu-24.04-arm
     timeout-minutes: 8
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           path: trusted
diff --git a/.github/workflows/comment.yml b/.github/workflows/comment.yml
index ab56a3608d0f..73b6e03bfa40 100644
--- a/.github/workflows/comment.yml
+++ b/.github/workflows/comment.yml
@@ -23,7 +23,7 @@ jobs:
     timeout-minutes: 2
     if: contains(github.event.comment.body, '@NixOS/nixpkgs-merge-bot merge')
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout: |
diff --git a/.github/workflows/eval.yml b/.github/workflows/eval.yml
index f971aa0229da..16a758aba5f9 100644
--- a/.github/workflows/eval.yml
+++ b/.github/workflows/eval.yml
@@ -50,7 +50,7 @@ jobs:
       ciPinBumpCommit: ${{ steps.find-pinned-commit.outputs.ciPinBumpCommit }}
       ciPinBumpCommitShort: ${{ steps.find-pinned-commit.outputs.ciPinBumpCommitShort }}
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           path: trusted
@@ -58,13 +58,16 @@ jobs:
             ci/supportedVersions.nix
 
       - name: Check out the PR at the test merge commit
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           ref: ${{ inputs.mergedSha }}
           path: untrusted
           sparse-checkout: |
             ci/pinned.json
+          # ci/pinned.json is only read as data by trusted/ci/supportedVersions.nix,
+          # so checking out the fork PR's merge commit is safe here.
+          allow-unsafe-pr-checkout: true
 
       - name: Find commit that touched ci/pinned.json
         id: find-pinned-commit
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 11bf76a7dbd6..ef2a63b0962b 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -122,7 +122,7 @@ jobs:
     runs-on: ubuntu-24.04-arm
     timeout-minutes: 8
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: true # Needed to run git fetch for large PRs.
           path: trusted
diff --git a/.github/workflows/merge-group.yml b/.github/workflows/merge-group.yml
index e2ef4e77fe9c..a53f38f194df 100644
--- a/.github/workflows/merge-group.yml
+++ b/.github/workflows/merge-group.yml
@@ -25,7 +25,7 @@ jobs:
       targetSha: ${{ steps.prepare.outputs.targetSha }}
       systems: ${{ steps.prepare.outputs.systems }}
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout: |
diff --git a/.github/workflows/periodic-merge.yml b/.github/workflows/periodic-merge.yml
index d84de7d4b26a..9398f3ea2310 100644
--- a/.github/workflows/periodic-merge.yml
+++ b/.github/workflows/periodic-merge.yml
@@ -34,7 +34,7 @@ jobs:
           permission-contents: write
           permission-issues: write
 
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
 
diff --git a/.github/workflows/pull-request-target.yml b/.github/workflows/pull-request-target.yml
index 98d463cb588d..0c90a89dabb2 100644
--- a/.github/workflows/pull-request-target.yml
+++ b/.github/workflows/pull-request-target.yml
@@ -36,7 +36,7 @@ jobs:
       systems: ${{ steps.prepare.outputs.systems }}
       touched: ${{ steps.prepare.outputs.touched }}
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout-cone-mode: true # default, for clarity
diff --git a/.github/workflows/review.yml b/.github/workflows/review.yml
index 9e5d32e81315..caf9421ff45b 100644
--- a/.github/workflows/review.yml
+++ b/.github/workflows/review.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-slim
     timeout-minutes: 2
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout: |
diff --git a/.github/workflows/teams.yml b/.github/workflows/teams.yml
index 5e8e20497b7f..8bf0e0419c19 100644
--- a/.github/workflows/teams.yml
+++ b/.github/workflows/teams.yml
@@ -30,7 +30,7 @@ jobs:
           permission-pull-requests: write
 
       - name: Fetch source
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout: |
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f5a6c1bfcec4..cb00b3367b1e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -19,7 +19,7 @@ jobs:
       push: ${{ steps.files.outputs.push }}
       targetSha: ${{ steps.prepare.outputs.targetSha }}
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
           sparse-checkout-cone-mode: true # default, for clarity