Security audit 2026-10-14: CI hardening and Dependabot security-only

.github/dependabot.yml

@@ -1,20 +1,23 @@
-# To get started with Dependabot version updates, you'll need to specify which
-# package ecosystems to update and where the package manifests are located.
-# https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#versioning-strategy
+# Dependabot: security updates only (no version-update PRs).
+# Grouped security PRs open weekly on Tuesday morning (Europe/Bucharest).
+# Auto-merge: .github/workflows/dependabot-auto-merge.yml (on PR + Tuesday cron).
+# https://docs.github.com/en/code-security/dependabot/dependabot-security-updates
 
 version: 2
 updates:
-  # Keep the Github Actions dependencies up to date
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
-      day: "monday"
-    target-branch: "main"
+      interval: weekly
+      day: tuesday
+      time: "06:00"
+      timezone: Europe/Bucharest
+    open-pull-requests-limit: 0
     labels:
+      - "dependabot-security"
       - "github dependencies"
     groups:
-      github:
-        applies-to: version-updates
+      github-actions-security:
+        applies-to: security-updates
         patterns:
           - "*"

.github/workflows/auto_assign_ci.yaml

@@ -1,4 +1,5 @@
 name: Auto Assign
+# Audit 2026-10-14: pull_request_target — do not checkout the PR head here; configuration-path only.
 
 on:
   pull_request_target:
@@ -16,6 +17,6 @@ jobs:
     name: Auto assign (me only)
     runs-on: ubuntu-latest
     steps:
-      - uses: kentaro-m/auto-assign-action@v2.0.2
+      - uses: kentaro-m/auto-assign-action@0a2c53d3721e4c5cfcce6afd4014aecc337979f6 # v2.0.2
         with:
           configuration-path: ".github/auto_assign.yml"

.github/workflows/codeql.yml

@@ -61,7 +61,7 @@ jobs:
         # your codebase is analyzed, see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/codeql-code-scanning-for-compiled-languages
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v7
+      uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
     # Add any setup steps before running the `github/codeql-action/init` action.
     # This includes steps like installing compilers or runtimes (`actions/setup-node`
@@ -71,7 +71,7 @@ jobs:
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4.37.8
+      uses: github/codeql-action/init@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4.37.8
       with:
         languages: ${{ matrix.language }}
         build-mode: ${{ matrix.build-mode }}
@@ -100,23 +100,23 @@ jobs:
         exit 1
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4.37.8
+      uses: github/codeql-action/analyze@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4.37.8
       with:
         category: "/language:${{matrix.language}}"
         output: sarif-results
         upload: never
 
     # Exclude alerts in fetched dependencies (e.g. curl parsedate.c) from code scanning results
     - name: Filter dependency alerts from SARIF
-      uses: advanced-security/filter-sarif@v1
+      uses: advanced-security/filter-sarif@f3b8118a9349d88f7b1c0c488476411145b6270d # v1.0.1
       with:
         patterns: |
           -**/curl-src/**
         input: sarif-results/cpp.sarif
         output: sarif-results/cpp.sarif
 
     - name: Upload SARIF
-      uses: github/codeql-action/upload-sarif@v4.37.8
+      uses: github/codeql-action/upload-sarif@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4.37.8
       with:
         sarif_file: sarif-results
         category: "/language:${{matrix.language}}"

.github/workflows/dependabot-auto-merge.yml

@@ -0,0 +1,50 @@
+name: Dependabot security auto-merge
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+  schedule:
+    - cron: "0 6 * * 2"
+      timezone: Europe/Bucharest
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  approve-and-queue-merge:
+    runs-on: ubuntu-latest
+    if: >-
+      github.event_name == 'pull_request'
+      && github.event.pull_request.user.login == 'dependabot[bot]'
+    steps:
+      - name: Approve Dependabot pull request
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Enable auto-merge when checks pass
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  weekly-merge-ready:
+    runs-on: ubuntu-latest
+    if: github.event_name == 'schedule'
+    steps:
+      - name: Approve and queue merge for open Dependabot PRs
+        run: |
+          set -euo pipefail
+          mapfile -t urls < <(gh pr list --author app/dependabot --state open --json url --jq '.[].url')
+          if [ "${#urls[@]}" -eq 0 ]; then
+            echo "No open Dependabot pull requests."
+            exit 0
+          fi
+          for url in "${urls[@]}"; do
+            gh pr review --approve "$url" || true
+            gh pr merge --auto --merge "$url" || true
+          done
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/publish.yml

@@ -13,23 +13,36 @@ permissions:
 
 jobs:
   validate-tag:
+    outputs:
+      tag_sha: ${{ steps.tag_sha.outputs.sha }}
     name: Validate tag
     runs-on: ubuntu-latest
     steps:
+      - name: Validate tag input
+        env:
+          TAG: ${{ github.event.inputs.tag }}
+        run: |
+          re='^v?[0-9]+\.[0-9]+\.[0-9]+([.+-][0-9A-Za-z.-]+)?$'
+          if [[ ! "$TAG" =~ $re ]]; then
+            echo "Error: the tag input must be a release tag such as v1.2.3."
+            exit 1
+          fi
+
       - name: Checkout
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           fetch-depth: 0
-          ref: ${{ github.event.inputs.tag }}
+          ref: refs/tags/${{ github.event.inputs.tag }}
 
+          persist-credentials: false
       - name: Verify tag and project version
         run: |
           TAG="${{ github.event.inputs.tag }}"
           if [ -z "$TAG" ]; then
             echo "Error: Tag is required."
             exit 1
           fi
-          if ! git rev-parse "$TAG" >/dev/null 2>&1; then
+          if ! git rev-parse -q --verify "refs/tags/$TAG" >/dev/null; then
             echo "Error: Tag '$TAG' does not exist."
             exit 1
           fi
@@ -43,7 +56,14 @@ jobs:
             echo "Error: CMakeLists.txt version ($PKG_VERSION) does not match tag ($TAG)."
             exit 1
           fi
-          echo "Publishing tag: $TAG (ZeroBounce C++ SDK $PKG_VERSION)"
+
+      - name: Record tag commit SHA
+        id: tag_sha
+        env:
+          TAG: ${{ github.event.inputs.tag }}
+        run: |
+          SHA=$(git rev-parse "refs/tags/$TAG^{commit}")
+          echo "sha=$SHA" >> "$GITHUB_OUTPUT"
 
   test:
     name: Test
@@ -52,10 +72,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout tag
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
-          ref: ${{ github.event.inputs.tag }}
-
+          ref: ${{ needs.validate-tag.outputs.tag_sha }}
+          persist-credentials: false
       - name: Install build dependencies
         run: |
           sudo apt-get update
@@ -69,28 +89,29 @@ jobs:
 
   release:
     name: Create GitHub Release
-    needs: [test]
+    needs: [validate-tag, test]
     if: ${{ !cancelled() && !failure() }}
     runs-on: ubuntu-latest
     permissions:
       contents: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
-          ref: ${{ github.event.inputs.tag }}
+          ref: ${{ needs.validate-tag.outputs.tag_sha }}
           fetch-depth: 0
 
+          persist-credentials: false
       - name: Create release if missing
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           TAG="${{ github.event.inputs.tag }}"
-          if gh release view "$TAG" --repo "${{ github.repository }}" >/dev/null 2>&1; then
+          if gh release view "$TAG" --repo "$GITHUB_REPOSITORY" >/dev/null 2>&1; then
             echo "Release $TAG already exists, skipping."
           else
             gh release create "$TAG" \
-              --repo "${{ github.repository }}" \
+              --repo "$GITHUB_REPOSITORY" \
               --title "$TAG" \
               --generate-notes
           fi

.github/workflows/sdk_ci.yml

@@ -15,7 +15,9 @@ jobs:
     name: Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
 
       - name: Install build dependencies
         run: |

CMakeLists.txt

@@ -1,4 +1,8 @@
 cmake_minimum_required(VERSION 3.20)
+if(POLICY CMP0026)
+  cmake_policy(SET CMP0026 NEW)
+endif()
+set(CMAKE_POLICY_VERSION_MINIMUM 3.5)
 project(ZeroBounce VERSION 2.1.4 LANGUAGES CXX)
 
 set(CMAKE_CXX_STANDARD 20)
@@ -14,7 +18,7 @@ include(FetchContent)
 FetchContent_Declare(
     cpr
     GIT_REPOSITORY https://github.com/libcpr/cpr.git
-    GIT_TAG 1.10.2
+    GIT_TAG 1.11.2
 )
 # Download and build nlohmann_json
 FetchContent_Declare(

Dockerfile

@@ -13,8 +13,13 @@ WORKDIR /app
 
 COPY . .
 
-RUN cmake -S . -B build -G "Unix Makefiles" \
-    && cmake --build build
+RUN cmake -S . -B build -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release \
+    && cmake --build build \
+    && ctest --test-dir build --output-on-failure
+
+RUN useradd --uid 65532 --create-home --shell /usr/sbin/nologin zbtest \
+    && chown -R zbtest:zbtest /app
+
+USER zbtest
 
-# Run tests via CTest
 CMD ["ctest", "--test-dir", "build", "--output-on-failure"]

include/ZeroBounce/ZeroBounce.h

@@ -95,19 +95,19 @@ class BaseRequestHandler {
 class RequestHandler : public BaseRequestHandler {
     protected:
         cpr::Response doGet(const cpr::Url& url) {
-            return cpr::Get(url, cpr::Timeout{120000});
+            return cpr::Get(url, cpr::Timeout{120000}, cpr::Redirect{false});
         }
         cpr::Response doGet(const cpr::Url& url, const cpr::Header& header) {
-            return cpr::Get(url, header, cpr::Timeout{120000});
+            return cpr::Get(url, header, cpr::Timeout{120000}, cpr::Redirect{false});
         }
         cpr::Response doGetWithParameters(const cpr::Url& url, const cpr::Parameters& parameters) {
-            return cpr::Get(url, parameters, cpr::Timeout{120000});
+            return cpr::Get(url, parameters, cpr::Timeout{120000}, cpr::Redirect{false});
         }
         cpr::Response doPost(const cpr::Url& url, const cpr::Header& header, const cpr::Body& body) {
-            return cpr::Post(url, header, body, cpr::Timeout{120000});
+            return cpr::Post(url, header, body, cpr::Timeout{120000}, cpr::Redirect{false});
         }
         cpr::Response doPost(const cpr::Url& url, const cpr::Header& header, const cpr::Multipart& multipart) {
-            return cpr::Post(url, header, multipart, cpr::Timeout{120000});
+            return cpr::Post(url, header, multipart, cpr::Timeout{120000}, cpr::Redirect{false});
         }
 };
 

src/ZBDomainSearchResponse.cpp

@@ -53,7 +53,8 @@ ZBDomainSearchResponse ZBDomainSearchResponse::from_json(const json& json_obj) {
     response.failureReason = getOrDefault<std::string>(json_obj, "failure_reason", "");
 
     response.otherDomainFormats = std::vector<ZBDomainFormat>();
-    const json domainFormats = json_obj["other_domain_formats"];
+    const json domainFormats = json_obj.contains("other_domain_formats")
+        ? json_obj["other_domain_formats"] : json::array();
     if (domainFormats.is_array()) {
         for (int index = 0; index < domainFormats.size(); index ++) {
             response.otherDomainFormats.push_back(