diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6ce8ebc..8b34db2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,10 +9,10 @@ on:
 jobs:
   test:
     name: test + typecheck
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
         with:
           node-version: 20
           cache: npm
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index a8fddee..6d5aa7a 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -26,7 +26,7 @@ jobs:
     name: analyze (${{ matrix.language }})
     # Auto-skips on private repos; CodeQL is free on public ones.
     if: ${{ github.event.repository.visibility == 'public' }}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     permissions:
       actions: read
       contents: read
@@ -39,10 +39,10 @@ jobs:
         language: [javascript-typescript]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v3
+        uses: github/codeql-action/init@v4
         with:
           languages: ${{ matrix.language }}
           # 'security-and-quality' is the broadest preset — includes both
@@ -51,9 +51,9 @@ jobs:
           queries: security-and-quality
 
       - name: Build (autobuild for JS/TS — no-op compile)
-        uses: github/codeql-action/autobuild@v3
+        uses: github/codeql-action/autobuild@v4
 
       - name: Perform CodeQL analysis
-        uses: github/codeql-action/analyze@v3
+        uses: github/codeql-action/analyze@v4
         with:
           category: "/language:${{ matrix.language }}"
diff --git a/.github/workflows/deploy-prober.yml b/.github/workflows/deploy-prober.yml
index 95979c9..5d4bb3f 100644
--- a/.github/workflows/deploy-prober.yml
+++ b/.github/workflows/deploy-prober.yml
@@ -37,9 +37,9 @@ env:
 jobs:
   deploy:
     name: provision + deploy prober
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
       - name: Configure SSH
         env:
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
index 4989e1b..535a4ad 100644
--- a/.github/workflows/security.yml
+++ b/.github/workflows/security.yml
@@ -11,14 +11,14 @@ on:
 jobs:
   semgrep:
     name: semgrep
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     continue-on-error: true
     # Skip on cross-repo fork PRs — they can't write annotations.
     if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
     container:
       image: semgrep/semgrep
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
       # OSS scan only (no SaaS upload, no token). Block only on ERROR-severity
       # findings — anything WARNING / INFO is logged but doesn't fail the build.
       - run: |
@@ -34,11 +34,11 @@ jobs:
 
   npm-audit:
     name: npm audit
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v7
+      - uses: actions/setup-node@v7
         with:
           node-version: 20
       - name: Audit (skip when no package.json)
@@ -55,10 +55,10 @@ jobs:
 
   gitleaks:
     name: gitleaks
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
         with:
           fetch-depth: 0
       # OSS binary — no license shakedown for org-owned repos.
diff --git a/.github/workflows/threatcrush-scan.yml b/.github/workflows/threatcrush-scan.yml
index d9190b6..bb51acd 100644
--- a/.github/workflows/threatcrush-scan.yml
+++ b/.github/workflows/threatcrush-scan.yml
@@ -15,13 +15,13 @@ permissions:
 jobs:
   scan:
     name: Scan for credentials and vulnerable patterns
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v7
         with:
           node-version: "20"
 
@@ -151,7 +151,7 @@ jobs:
       - name: Upload to the Security tab
         if: always() && 'true' == 'true'
         continue-on-error: true
-        uses: github/codeql-action/upload-sarif@v3
+        uses: github/codeql-action/upload-sarif@v4
         with:
           sarif_file: threatcrush.sarif
           category: threatcrush
@@ -236,7 +236,7 @@ jobs:
 
       - name: Upload SARIF artifact
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: threatcrush-sarif
           path: threatcrush.sarif
@@ -251,7 +251,7 @@ jobs:
       - name: Comment on PR
         if: always() && github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]'
         continue-on-error: true
-        uses: actions/github-script@v7
+        uses: actions/github-script@v9
         with:
           script: |
             const fs = require('fs');