diff --git a/.github/workflows/gosec.yml b/.github/workflows/gosec.yml
new file mode 100644
index 00000000..d5cc742a
--- /dev/null
+++ b/.github/workflows/gosec.yml
@@ -0,0 +1,128 @@
+name: Gosec Security Scan
+
+# Port of the Lumera chain repo's `gosec.yml` (LumeraProtocol/lumera#213).
+#
+# Same tool, same policy: HIGH severity + HIGH confidence, suppressions must
+# carry both a rule ID and a justification (`-nosec-require-rules`,
+# `-nosec-require-justification`), results published to GitHub code scanning
+# as SARIF.
+#
+# Difference from the chain repo: supernode has four Go modules instead of
+# three. gosec's package loader walks a single module at a time, so each is
+# scanned from its own working directory. A root `./...` run does NOT cover
+# the nested modules.
+
+on:
+  pull_request:
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
+      - ".gitignore"
+  push:
+    branches: [master]
+
+permissions:
+  contents: read
+  security-events: write
+
+jobs:
+  gosec:
+    name: gosec (${{ matrix.name }})
+    runs-on: ubuntu-latest
+    timeout-minutes: 25
+    strategy:
+      # Report every module; one module's findings must not hide another's.
+      fail-fast: false
+      matrix:
+        include:
+          - name: supernode
+            module: .
+          - name: sncli
+            module: cmd/sncli
+          - name: sn-manager
+            module: sn-manager
+          - name: systemtests
+            module: tests/system
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6.0.1
+
+      # Installs Go from go.mod, libwebp-dev (required for the root module to
+      # type-check — without it gosec fails SSA construction rather than
+      # reporting a clean scan), and GOPRIVATE for the Lumera module.
+      - name: Setup Go and system deps
+        uses: ./.github/actions/setup-env
+
+      - name: Download Go modules
+        working-directory: ${{ matrix.module }}
+        run: go mod download
+
+      - name: Install gosec
+        run: go install github.com/securego/gosec/v2/cmd/gosec@v2.29.0
+
+      # No `continue-on-error` here: this is a blocking gate. `-stdout
+      # -verbose text` keeps findings readable in the job log even when the
+      # SARIF upload is skipped (fork PRs).
+      - name: Run gosec
+        working-directory: ${{ matrix.module }}
+        run: |
+          gosec \
+            -severity high \
+            -confidence high \
+            -nosec-require-rules \
+            -nosec-require-justification \
+            -fmt sarif \
+            -out gosec.sarif \
+            -stdout \
+            -verbose text \
+            ./...
+
+      # gosec emits artifact URIs relative to the scanned module, so findings
+      # from nested modules would otherwise be attributed to paths that do not
+      # exist at the repository root. Prefix them with the module directory.
+      - name: Normalize SARIF paths
+        if: ${{ always() && matrix.module != '.' }}
+        env:
+          GOSEC_MODULE: ${{ matrix.module }}
+          GOSEC_SARIF: ${{ matrix.module }}/gosec.sarif
+        run: |
+          python3 - <<'PY'
+          import json
+          import os
+          from pathlib import PurePosixPath
+          from urllib.parse import urlparse
+
+          sarif_path = os.environ["GOSEC_SARIF"]
+          module = os.environ["GOSEC_MODULE"].strip("/")
+          with open(sarif_path, encoding="utf-8") as sarif_file:
+              sarif = json.load(sarif_file)
+
+          def prefix_artifact_uris(value):
+              if isinstance(value, dict):
+                  artifact = value.get("artifactLocation")
+                  if isinstance(artifact, dict):
+                      uri = artifact.get("uri")
+                      if isinstance(uri, str) and uri and not urlparse(uri).scheme and not uri.startswith("/"):
+                          if not uri.startswith(module + "/"):
+                              artifact["uri"] = str(PurePosixPath(module) / uri)
+                  for child in value.values():
+                      prefix_artifact_uris(child)
+              elif isinstance(value, list):
+                  for child in value:
+                      prefix_artifact_uris(child)
+
+          prefix_artifact_uris(sarif)
+          with open(sarif_path, "w", encoding="utf-8") as sarif_file:
+              json.dump(sarif, sarif_file, separators=(",", ":"))
+          PY
+
+      # `security-events: write` is not granted to fork PRs, and dependabot
+      # runs with a read-only token, so skip only the upload for those. The
+      # scan itself still runs and still blocks.
+      - name: Upload SARIF
+        if: ${{ always() && (github.event_name != 'pull_request' || (github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]')) }}
+        uses: github/codeql-action/upload-sarif@v4
+        with:
+          sarif_file: ${{ matrix.module }}/gosec.sarif
+          category: gosec-${{ matrix.name }}
diff --git a/.github/workflows/govulncheck.yml b/.github/workflows/govulncheck.yml
new file mode 100644
index 00000000..765668a6
--- /dev/null
+++ b/.github/workflows/govulncheck.yml
@@ -0,0 +1,63 @@
+name: Go Vulnerability Scan
+
+# Port of the Lumera chain repo's `govulncheck.yml` (LumeraProtocol/lumera#212).
+#
+# Same tool, same goal: fail a PR when it introduces (or is built on) a
+# *reachable* known vulnerability. govulncheck's default mode only reports
+# vulnerabilities whose vulnerable symbols are actually called, so unused
+# transitive dependencies do not create noise.
+#
+# Difference from the chain repo: supernode is a multi-module repository
+# (root, cmd/sncli, sn-manager, tests/system). The chain repo scans a single
+# module; here each module is scanned independently via a matrix so a
+# vulnerability in sn-manager cannot hide behind a clean root scan.
+
+on:
+  pull_request:
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
+      - ".gitignore"
+  push:
+    branches: [master]
+
+permissions:
+  contents: read
+
+jobs:
+  govulncheck:
+    name: govulncheck (${{ matrix.name }})
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    strategy:
+      # Surface every module's result; do not let the first failure mask others.
+      fail-fast: false
+      matrix:
+        include:
+          - name: supernode
+            module: .
+          - name: sncli
+            module: cmd/sncli
+          - name: sn-manager
+            module: sn-manager
+          - name: systemtests
+            module: tests/system
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6.0.1
+
+      # Installs Go from go.mod, libwebp-dev (required to build the root
+      # module), and sets GOPRIVATE for the Lumera module.
+      - name: Setup Go and system deps
+        uses: ./.github/actions/setup-env
+
+      # Pinned rather than @latest: an unpinned scanner turns an unrelated
+      # upstream release into a surprise CI break, and makes a red run
+      # non-reproducible after the fact.
+      - name: Install govulncheck
+        run: go install golang.org/x/vuln/cmd/govulncheck@v1.1.4
+
+      - name: Run govulncheck
+        working-directory: ${{ matrix.module }}
+        run: govulncheck ./...
diff --git a/.github/workflows/lint-pr.yml b/.github/workflows/lint-pr.yml
new file mode 100644
index 00000000..e4718cf0
--- /dev/null
+++ b/.github/workflows/lint-pr.yml
@@ -0,0 +1,93 @@
+name: lint-pr
+
+# Port of the Lumera chain repo's `lint-pr.yml` (LumeraProtocol/lumera#126).
+#
+# Runs golangci-lint through reviewdog with `filter_mode: added`, so findings
+# are posted as inline review comments on exactly the lines a PR changed and
+# the pre-existing baseline stays invisible.
+#
+# IMPORTANT DIFFERENCE FROM THE CHAIN REPO:
+# The chain repo has a separate full-scan gate (`lint.yml`) that is the
+# authoritative merge blocker, which lets its reviewdog layer be purely
+# additive. Supernode has NO existing lint gate and a large legacy baseline,
+# so a full-repo hard gate would be red on day one. This workflow is therefore
+# the only lint enforcement, and it is intentionally scoped to the diff:
+# new code must be clean, legacy debt is not retroactively blocking.
+#
+# Version pinning (see below) is not cosmetic — go.mod declares go 1.26.2 and
+# golangci-lint must be BUILT with a Go >= that language version or it exits
+# with a hard "the Go language version used to build golangci-lint is lower
+# than the targeted Go version" error. v2.13.2 is built with go1.27.0.
+# reviewdog/action-golangci-lint must be >= v2.8.0 to honour a v2.x pin.
+
+on:
+  pull_request:
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
+      - ".gitignore"
+
+permissions:
+  contents: read
+  pull-requests: write   # reviewdog needs this to post inline review comments (same-repo PRs only)
+  checks: write          # for the check-run summary
+
+jobs:
+  golangci-lint-diff:
+    name: golangci-lint (diff-only, inline)
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6.0.1
+        with:
+          # reviewdog needs the merge-base to compute the PR diff.
+          fetch-depth: 0
+
+      # Installs Go from go.mod plus libwebp-dev, which the root module
+      # requires in order to type-check.
+      - name: Setup Go and system deps
+        uses: ./.github/actions/setup-env
+
+      # Same-repo PRs: post findings as inline review comments. The default
+      # GITHUB_TOKEN has the `pull-requests: write` scope declared above.
+      #
+      # We deliberately do NOT set `level` here: reviewdog's `level` input
+      # REWRITES every finding's severity rather than defaulting it, so
+      # `level: warning` combined with `fail_level: error` would silently
+      # neuter the gate. Leaving it unset preserves native severities so
+      # govet/staticcheck errors actually trip `fail_level: error`.
+      - name: golangci-lint via reviewdog (same-repo PR — inline comments)
+        if: github.event.pull_request.head.repo.full_name == github.repository
+        uses: reviewdog/action-golangci-lint@v2.10.0
+        with:
+          go_version_file: go.mod
+          golangci_lint_version: v2.13.2
+          golangci_lint_flags: "--config=.golangci.yml --timeout=15m"
+          workdir: .
+          # Only annotate lines actually changed by the PR.
+          filter_mode: added
+          reporter: github-pr-review
+          fail_level: error
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      # Fork PRs: GITHUB_TOKEN is strictly read-only regardless of the
+      # workflow-level permissions block, so neither `github-pr-review`
+      # (needs pull-requests: write) nor `github-pr-check` (needs
+      # checks: write) can post results. The `local` reporter writes findings
+      # to the job log instead. `fail_level: error` still fails the job, so
+      # the check continues to block merge for external contributors.
+      - name: golangci-lint via reviewdog (fork PR — log-only)
+        if: github.event.pull_request.head.repo.full_name != github.repository
+        uses: reviewdog/action-golangci-lint@v2.10.0
+        with:
+          go_version_file: go.mod
+          golangci_lint_version: v2.13.2
+          golangci_lint_flags: "--config=.golangci.yml --timeout=15m"
+          workdir: .
+          filter_mode: added
+          reporter: local
+          fail_level: error
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 00000000..eed0b116
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,77 @@
+version: "2"
+
+# Linter policy for the supernode repo.
+#
+# Mirrors the Lumera chain repo's `.golangci.yml` (same linter set, same
+# v2 schema) so both repos enforce a consistent bar. The exclusion list is
+# supernode-specific: it covers generated protobuf/mock surfaces and test
+# helpers rather than the chain's Cosmos SDK deprecations.
+#
+# Enforcement is diff-only via reviewdog (`.github/workflows/lint-pr.yml`),
+# so the pre-existing baseline is not a merge blocker; only findings on
+# lines a PR actually touches are reported.
+
+linters:
+  default: none
+  enable:
+    - errcheck
+    - staticcheck
+    - unused
+    - ineffassign
+    - govet
+    - nolintlint
+
+  exclusions:
+    generated: strict
+    rules:
+      # Test files: setup helpers routinely ignore errors from fixture
+      # construction where a failure would surface as a test failure anyway.
+      - path: _test\.go
+        linters:
+          - errcheck
+
+      # Generated gRPC/protobuf gateway + mock surfaces.
+      - path: (gen/|/mocks?/|\.pb\.go|\.pb\.gw\.go)
+        linters:
+          - errcheck
+          - unused
+          - staticcheck
+
+      # SDK deprecated APIs — cannot be removed until upstream drops them.
+      - linters:
+          - staticcheck
+        text: "SA1019"
+
+      # Cosmetic quick-fix suggestions (QF1003/QF1007/QF1008/QF1011).
+      - linters:
+          - staticcheck
+        text: "QF10(0[378]|11)"
+
+      # S1001 (use copy), S1009 (nil check before len), S1011 (use append),
+      # S1021 (merge var) — cosmetic, not correctness issues.
+      - linters:
+          - staticcheck
+        text: "S100[19]|S101[1]|S1021"
+
+      # ST1005 (error string capitalization), ST1019 (duplicate import),
+      # ST1023 (omit type from declaration) — style, not correctness.
+      - linters:
+          - staticcheck
+        text: "ST10(05|19|23)"
+
+      # SA4031 (nil check on make result), SA9003 (empty branch) —
+      # intentional patterns in existing code.
+      - linters:
+          - staticcheck
+        text: "SA(4031|9003)"
+
+      # SA1029 (built-in type as context key) — existing pattern.
+      - linters:
+          - staticcheck
+        text: "SA1029"
+
+formatters:
+  enable:
+    - gofmt
+  exclusions:
+    generated: strict
diff --git a/cmd/sncli/cli/utils.go b/cmd/sncli/cli/utils.go
index 15e893a3..801826fd 100644
--- a/cmd/sncli/cli/utils.go
+++ b/cmd/sncli/cli/utils.go
@@ -25,6 +25,8 @@ func NormalizePath(path string) string {
 func processConfigPath(path string) string {
 	path = NormalizePath(path)
 	// check if path defines directory
+	// #nosec G703 -- path is an explicit operator-supplied --config value for
+	// a local CLI, already normalized/cleaned above; only stat'ed here.
 	if info, err := os.Stat(path); err == nil && info.IsDir() {
 		path = filepath.Join(path, defaultConfigFileName)
 	}
diff --git a/sn-manager/cmd/helpers.go b/sn-manager/cmd/helpers.go
index 3187e069..e52263b7 100644
--- a/sn-manager/cmd/helpers.go
+++ b/sn-manager/cmd/helpers.go
@@ -50,6 +50,8 @@ func ensureSupernodeInitialized() error {
 		userHome = os.Getenv("HOME")
 	}
 	supernodeConfigPath := filepath.Join(userHome, ".supernode", "config.yml")
+	// #nosec G703 -- path is derived from the operator's own home directory
+	// (os.UserHomeDir/$HOME), not from untrusted input, and is only stat'ed.
 	if _, err := os.Stat(supernodeConfigPath); os.IsNotExist(err) {
 		return fmt.Errorf("SuperNode not initialized. Please run 'sn-manager init' first to configure your validator keys and network settings")
 	}
diff --git a/sn-manager/cmd/init.go b/sn-manager/cmd/init.go
index cebbeb83..acba2482 100644
--- a/sn-manager/cmd/init.go
+++ b/sn-manager/cmd/init.go
@@ -237,6 +237,8 @@ func runInit(cmd *cobra.Command, args []string) error {
 		userHome = os.Getenv("HOME")
 	}
 	supernodeConfigPath := filepath.Join(userHome, ".supernode", "config.yml")
+	// #nosec G703 -- path is derived from the operator's own home directory
+	// (os.UserHomeDir/$HOME), not from untrusted input, and is only stat'ed.
 	if _, err := os.Stat(supernodeConfigPath); err == nil {
 		fmt.Println("✓ SuperNode already initialized, skipping initialization")
 	} else {
diff --git a/supernode/transport/gateway/server.go b/supernode/transport/gateway/server.go
index 55985335..a4e2e830 100644
--- a/supernode/transport/gateway/server.go
+++ b/supernode/transport/gateway/server.go
@@ -5,6 +5,11 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	// #nosec G108 -- importing net/http/pprof registers handlers on
+	// http.DefaultServeMux, but this server never serves DefaultServeMux. The
+	// pprof routes below are registered on a private mux and are only wired up
+	// when pprofEnabled (testnet chain-id or ENABLE_PPROF=true); the handlers
+	// additionally re-check that flag and return 403 otherwise.
 	_ "net/http/pprof"
 	"os"
 	"strconv"
diff --git a/tests/system/system.go b/tests/system/system.go
index 5a1adbb9..1fddd3c7 100644
--- a/tests/system/system.go
+++ b/tests/system/system.go
@@ -205,6 +205,8 @@ func disableStateSyncConfig(configPath string) error {
 	if info, err := os.Stat(configPath); err == nil {
 		perm = info.Mode().Perm()
 	}
+	// #nosec G703 -- test harness: configPath is a node home directory created
+	// by this system-test suite itself, not untrusted input.
 	return os.WriteFile(configPath, []byte(strings.Join(lines, "\n")), perm)
 }