diff --git a/.github/workflows/gotip-testing.yml b/.github/workflows/gotip-testing.yml
index a6f5dd7c1bd..a2dc7916fdf 100644
--- a/.github/workflows/gotip-testing.yml
+++ b/.github/workflows/gotip-testing.yml
@@ -6,7 +6,7 @@ on:
   workflow_dispatch: { } # manually
 
 env:
-  TEST_RESULTS: /tmp/tip-results # path to where test results will be saved
+  TEST_RESULTS: ${{ github.workspace }}/tip-results # path to where test results will be saved
 
 permissions:
   id-token: write
@@ -43,28 +43,88 @@ jobs:
           ref: ${{ github.ref }}
           repository: DataDog/dd-trace-go
 
-      - name: Get Gotip
-        run: |-
-          go install golang.org/dl/gotip@latest
-          echo "$HOME/go/bin" >> "$GITHUB_PATH"
-          echo "${{ github.workspace }}/bin" >> "$GITHUB_PATH"
+      - name: Setup Go
+        uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5.6.0
+        with:
+          go-version: stable
+          cache-dependency-path: '**/go.sum'
+
+      - name: Capture trusted commit SHA
+        # Pinned before any sandboxed step so we can re-checkout this exact
+        # commit after the sandbox runs. Anything that escapes the sandbox
+        # could otherwise rewrite .git/HEAD or refs and trick the host into
+        # running attacker-controlled code via local actions.
+        id: trusted
+        run: echo "sha=$(git rev-parse HEAD)" >> "${GITHUB_OUTPUT}"
+
+      - name: Run tests with gotip (sandboxed)
+        # gotip pulls and runs the latest Go toolchain. Keep that toolchain and
+        # the test process inside gVisor, persisting only reports/coverage.
+        uses: geomys/sandboxed-step@7d75eb49d17fdeeb3656b3a57d35932d205bcfb9 # v1.2.1
+        with:
+          persist-workspace-changes: 'true'
+          env: |
+            DD_APPSEC_WAF_TIMEOUT=1h
+            GO_CMD=gotip
+            TEST_RESULTS=${{ env.TEST_RESULTS }}
+          run: |-
+            mkdir -p "${GITHUB_WORKSPACE}/bin"
+            GOBIN="${GITHUB_WORKSPACE}/bin" go install golang.org/dl/gotip@latest
+            export PATH="${GITHUB_WORKSPACE}/bin:${PATH}"
+            ./scripts/install_tools.sh --bin-dir "${GITHUB_WORKSPACE}/bin"
+            gotip download
+            ./scripts/ci_test_core.sh
 
-      - name: Download dependencies
-        env:
-          GO_CMD: gotip
+      - name: Stage sandbox artifacts outside workspace
+        # Move the test results and coverage files to RUNNER_TEMP so the
+        # next checkout (which wipes the workspace) does not delete them.
+        # Only regular files are staged, to avoid following any symlinks
+        # that may have been planted inside the sandbox.
+        id: stage
+        if: always()
         run: |-
-          ./scripts/install_tools.sh --bin-dir ${{ github.workspace }}/bin
-          gotip download
+          set -euo pipefail
+          SAFE="${RUNNER_TEMP}/sandbox-artifacts"
+          rm -rf "${SAFE}"
+          mkdir -p "${SAFE}"
+          if [ -d "${TEST_RESULTS}" ]; then
+            ( cd "${TEST_RESULTS}" && find . -type f -print0 \
+              | tar --null --no-recursion -T - -cf "${SAFE}/test-results.tar" )
+          fi
+          ( cd "${GITHUB_WORKSPACE}" \
+            && find . -type f \( -name 'coverage*.txt' -o -name 'profile.cov' \) -print0 \
+            | tar --null --no-recursion -T - -cf "${SAFE}/coverage.tar" ) || true
 
-      - name: Run tests
-        env:
-          DD_APPSEC_WAF_TIMEOUT: 1h
-          TEST_RESULTS: ${{ env.TEST_RESULTS }}
-          GO_CMD: gotip
-        run: ./scripts/ci_test_core.sh
+      - name: Re-checkout trusted commit after sandbox
+        # Wipe the (potentially tampered) workspace and check out the SHA we
+        # captured before the sandbox ran. This restores .git, tracked files,
+        # and any local actions to a known-good state before any credentialed
+        # local action is invoked.
+        id: recheckout
+        if: always()
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+          ref: ${{ steps.trusted.outputs.sha }}
+          repository: DataDog/dd-trace-go
+          clean: true
+
+      - name: Restore sandbox artifacts
+        id: restore
+        if: always() && steps.recheckout.outcome == 'success'
+        run: |-
+          set -euo pipefail
+          SAFE="${RUNNER_TEMP}/sandbox-artifacts"
+          mkdir -p "${TEST_RESULTS}"
+          if [ -f "${SAFE}/test-results.tar" ]; then
+            tar -C "${TEST_RESULTS}" -xf "${SAFE}/test-results.tar"
+          fi
+          if [ -f "${SAFE}/coverage.tar" ]; then
+            tar -C "${GITHUB_WORKSPACE}" -xf "${SAFE}/coverage.tar"
+          fi
 
       - name: Upload the results to Datadog CI App
-        if: always()
+        if: always() && steps.restore.outcome == 'success'
         continue-on-error: true
         uses: ./.github/actions/dd-ci-upload
         with:
@@ -73,7 +133,7 @@ jobs:
           tags: go:gotip,arch:${{ runner.arch }},os:${{ runner.os }}
 
       - name: Upload Coverage
-        if: always()
+        if: always() && steps.restore.outcome == 'success'
         continue-on-error: true
         uses: ./.github/actions/codecov-upload
         with:
diff --git a/.github/workflows/govulncheck.yml b/.github/workflows/govulncheck.yml
index 45c3faa9c85..7d95a6ec4c3 100644
--- a/.github/workflows/govulncheck.yml
+++ b/.github/workflows/govulncheck.yml
@@ -41,11 +41,11 @@ permissions:
 jobs:
   # Non-blocking: generates SARIF and uploads to GitHub Code Scanning.
   # Replaces Dependabot Security Alerts with reachability-aware findings.
-  # Uses the official golang/govulncheck-action — see PR description for
+  # Uses the official golang/govulncheck-action — see PR #4599 for
   # the enterprise allowlist request context.
   # NOTE: Only core packages are scanned here. Contrib modules are scanned
-  # separately in govulncheck-contribs-analysis (SARIF, non-blocking) and
-  # in govulncheck-tests (blocking, sandboxed).
+  # separately in govulncheck-contribs-analysis (SARIF, non-blocking,
+  # sandboxed) and in govulncheck-tests (blocking, sandboxed).
   govulncheck-analysis:
     runs-on: ubuntu-latest
     steps:
@@ -114,15 +114,28 @@ jobs:
         with:
           go-version: stable
           cache-dependency-path: '**/go.sum'
-      - name: Run govulncheck on contrib modules (SARIF)
+      - name: Run govulncheck on contrib modules (SARIF, sandboxed)
+        # geomys/sandboxed-step uses gVisor to confine execution, preventing
+        # supply chain attacks from exfiltrating tokens or making network calls.
         # Installs govulncheck and runs govulncheck-contribs-sarif.sh, which
         # scans each contrib module and merges results into one SARIF file.
         # -format sarif exits 0 even when vulnerabilities are found.
-        run: |
-          go install golang.org/x/vuln/cmd/govulncheck@latest
-          ./.github/workflows/apps/govulncheck-contribs-sarif.sh govulncheck-contribs.sarif
-      - name: Upload contrib SARIF to GitHub Code Scanning
+        uses: geomys/sandboxed-step@7d75eb49d17fdeeb3656b3a57d35932d205bcfb9 # v1.2.1
+        with:
+          persist-workspace-changes: 'true'
+          run: |-
+            mkdir -p "${GITHUB_WORKSPACE}/bin"
+            GOBIN="${GITHUB_WORKSPACE}/bin" go install golang.org/x/vuln/cmd/govulncheck@latest
+            export PATH="${GITHUB_WORKSPACE}/bin:${PATH}"
+            ./.github/workflows/apps/govulncheck-contribs-sarif.sh govulncheck-contribs.sarif
+      - name: Restore workspace after sandbox
+        id: restore
         if: always()
+        run: |-
+          git reset --hard HEAD
+          git clean -fdx -e govulncheck-contribs.sarif
+      - name: Upload contrib SARIF to GitHub Code Scanning
+        if: always() && steps.restore.outcome == 'success' && hashFiles('govulncheck-contribs.sarif') != ''
         uses: github/codeql-action/upload-sarif@38697555549f1db7851b81482ff19f1fa5c4fedc # v4.34.1
         with:
           sarif_file: govulncheck-contribs.sarif
@@ -130,6 +143,7 @@ jobs:
 
   # Blocking: fails the build if any reachable vulnerability is found.
   # Scans both core packages and all contrib modules (each with its own go.mod).
+  # govulncheck execution is sandboxed via geomys/sandboxed-step (gVisor).
   govulncheck-tests:
     runs-on: ubuntu-latest
     steps:
@@ -142,9 +156,14 @@ jobs:
         with:
           go-version: stable
           cache-dependency-path: '**/go.sum'
-      - name: Install govulncheck
-        run: go install golang.org/x/vuln/cmd/govulncheck@latest
-      - name: Run govulncheck (core)
-        run: govulncheck ./ddtrace/... ./appsec/... ./profiler/... ./internal/... ./instrumentation/...
-      - name: Run govulncheck (contrib)
-        run: ./.github/workflows/apps/govulncheck-contribs-v2.sh
+      - name: Run govulncheck (sandboxed)
+        # geomys/sandboxed-step uses gVisor to confine execution, preventing
+        # supply chain attacks from exfiltrating tokens or making network calls.
+        uses: geomys/sandboxed-step@7d75eb49d17fdeeb3656b3a57d35932d205bcfb9 # v1.2.1
+        with:
+          run: |
+            mkdir -p "${GITHUB_WORKSPACE}/bin"
+            GOBIN="${GITHUB_WORKSPACE}/bin" go install golang.org/x/vuln/cmd/govulncheck@latest
+            export PATH="${GITHUB_WORKSPACE}/bin:${PATH}"
+            govulncheck ./ddtrace/... ./appsec/... ./profiler/... ./internal/... ./instrumentation/...
+            ./.github/workflows/apps/govulncheck-contribs-v2.sh
diff --git a/.github/workflows/smoke-tests.yml b/.github/workflows/smoke-tests.yml
index 5e36e2618a2..d35fea8244f 100644
--- a/.github/workflows/smoke-tests.yml
+++ b/.github/workflows/smoke-tests.yml
@@ -55,24 +55,29 @@ jobs:
           tools-dir: ${{ github.workspace }}/_tools
           tools-bin: ${{ github.workspace }}/bin
 
-      - name: go get -u
-        run: |-
-          mkdir -p "$TEST_RESULTS"
-          # shellcheck disable=SC2086
-          go get -u -t $PACKAGES
-          go mod tidy
-          find . -iname go.mod -exec dirname {} \; | while read -r d; do pushd "$d" && go mod tidy && popd; done
-
-      - name: Install requested go-libddwaf version
-        if: github.event_name == 'workflow_call' && inputs.go-libddwaf-ref != ''
-        run: |-
-          go get -u -t github.com/DataDog/go-libddwaf/v4@${{ inputs.go-libddwaf-ref }}
-          go mod tidy
-
-      - name: Compile dd-trace-go
-        run: |
-          # shellcheck disable=SC2086
-          go build $PACKAGES
+      - name: Compile dd-trace-go with updated dependencies (sandboxed)
+        # go get -u executes dependency code from the network. Keep those
+        # changes inside the gVisor sandbox; this setup job only needs to prove
+        # the updated dependency graph still compiles.
+        uses: geomys/sandboxed-step@7d75eb49d17fdeeb3656b3a57d35932d205bcfb9 # v1.2.1
+        with:
+          env: |
+            GOPROXY=${{ env.GOPROXY }}
+            GO_LIBDDWAF_REF=${{ inputs.go-libddwaf-ref }}
+            PACKAGES=${{ env.PACKAGES }}
+            TEST_RESULTS=${{ env.TEST_RESULTS }}
+          run: |-
+            mkdir -p "$TEST_RESULTS"
+            # shellcheck disable=SC2086
+            go get -u -t $PACKAGES
+            go mod tidy
+            find . -iname go.mod -exec dirname {} \; | while read -r d; do pushd "$d" && go mod tidy && popd; done
+            if [ -n "${GO_LIBDDWAF_REF:-}" ]; then
+              go get -u -t "github.com/DataDog/go-libddwaf/v4@${GO_LIBDDWAF_REF}"
+              go mod tidy
+            fi
+            # shellcheck disable=SC2086
+            go build $PACKAGES
 
       - name: Compute Matrix
         id: matrix
@@ -92,6 +97,8 @@ jobs:
         chunk: ${{ fromJson(needs.setup-env.outputs.matrix) }}
     runs-on: ubuntu-latest
     if: github.repository_owner == 'DataDog' # only run on DataDog's repository, not in forks
+    env:
+      TEST_RESULTS: ${{ github.workspace }}/test-results
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
@@ -108,19 +115,80 @@ jobs:
           go-version: stable
           tools-dir: ${{ github.workspace }}/_tools
           tools-bin: ${{ github.workspace }}/bin
-      - name: Test contribs
+      - name: Capture trusted commit SHA
+        # Pinned before any sandboxed step so we can re-checkout this exact
+        # commit after the sandbox runs. Anything that escapes the sandbox
+        # could otherwise rewrite .git/HEAD or refs and trick the host into
+        # running attacker-controlled code via local actions.
+        id: trusted
+        run: echo "sha=$(git rev-parse HEAD)" >> "${GITHUB_OUTPUT}"
+      - name: Test contribs (sandboxed)
         # It needs to run before "Test dd-trace-go" to avoid TestTelemetryEnabled tests to fail.
+        # The smoke script runs go get -u inside each contrib module, so run it
+        # in gVisor and persist only the generated reports/coverage for uploads.
+        uses: geomys/sandboxed-step@7d75eb49d17fdeeb3656b3a57d35932d205bcfb9 # v1.2.1
+        with:
+          persist-workspace-changes: 'true'
+          env: |
+            GOPROXY=${{ env.GOPROXY }}
+            TEST_RESULTS=${{ env.TEST_RESULTS }}
+          run: |-
+            export PATH="${GITHUB_WORKSPACE}/bin:${PATH}"
+            ./scripts/ci_test_contrib.sh smoke ${{ toJson(matrix.chunk) }}
+      - name: Stage sandbox artifacts outside workspace
+        # Move the test results and coverage files to RUNNER_TEMP so the
+        # next checkout (which wipes the workspace) does not delete them.
+        # Only regular files are staged, to avoid following any symlinks
+        # that may have been planted inside the sandbox.
+        id: stage
+        if: always()
         run: |-
-          export PATH="${{ github.workspace }}/bin:${PATH}"
-          ./scripts/ci_test_contrib.sh smoke ${{ toJson(matrix.chunk) }}
+          set -euo pipefail
+          SAFE="${RUNNER_TEMP}/sandbox-artifacts"
+          rm -rf "${SAFE}"
+          mkdir -p "${SAFE}"
+          if [ -d "${TEST_RESULTS}" ]; then
+            ( cd "${TEST_RESULTS}" && find . -type f -print0 \
+              | tar --null --no-recursion -T - -cf "${SAFE}/test-results.tar" )
+          fi
+          ( cd "${GITHUB_WORKSPACE}" \
+            && find . -type f \( -name 'coverage*.txt' -o -name 'profile.cov' \) -print0 \
+            | tar --null --no-recursion -T - -cf "${SAFE}/coverage.tar" ) || true
+      - name: Re-checkout trusted commit after sandbox
+        # Wipe the (potentially tampered) workspace and check out the SHA we
+        # captured before the sandbox ran. This restores .git, tracked files,
+        # and any local actions to a known-good state before any credentialed
+        # local action is invoked.
+        id: recheckout
+        if: always()
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+          ref: ${{ steps.trusted.outputs.sha }}
+          repository: DataDog/dd-trace-go
+          clean: true
+      - name: Restore sandbox artifacts
+        id: restore
+        if: always() && steps.recheckout.outcome == 'success'
+        run: |-
+          set -euo pipefail
+          SAFE="${RUNNER_TEMP}/sandbox-artifacts"
+          mkdir -p "${TEST_RESULTS}"
+          if [ -f "${SAFE}/test-results.tar" ]; then
+            tar -C "${TEST_RESULTS}" -xf "${SAFE}/test-results.tar"
+          fi
+          if [ -f "${SAFE}/coverage.tar" ]; then
+            tar -C "${GITHUB_WORKSPACE}" -xf "${SAFE}/coverage.tar"
+          fi
       - name: Get Datadog credentials
         id: dd-sts
+        if: always() && steps.restore.outcome == 'success'
         continue-on-error: true
         uses: DataDog/dd-sts-action@2e8187910199bd93129520183c093e19aa585c75
         with:
           policy: dd-trace-go
       - name: Upload the results to Datadog CI App
-        if: always()
+        if: always() && steps.restore.outcome == 'success'
         continue-on-error: true
         uses: ./.github/actions/dd-ci-upload
         with:
@@ -128,7 +196,7 @@ jobs:
           path: ${{ env.TEST_RESULTS }}
           tags: go:stable,arch:${{ runner.arch }},os:${{ runner.os }}
       - name: Upload Coverage
-        if: always()
+        if: always() && steps.restore.outcome == 'success'
         continue-on-error: true
         uses: ./.github/actions/codecov-upload
         with: