diff --git a/.github/.gitleaksignore b/.github/.gitleaksignore
new file mode 100644
index 0000000..c36d77f
--- /dev/null
+++ b/.github/.gitleaksignore
@@ -0,0 +1,3 @@
+# gitleaks false positives, by fingerprint. Each was read; none is a secret.
+# docs/build-host.md: quotes the fingerprint of the public TurnKey signing key.
+a4b120acec491eae56859d64413a55ddb566e253:docs/build-host.md:generic-api-key:213
diff --git a/.github/security-baseline b/.github/security-baseline
new file mode 100644
index 0000000..57d15d4
--- /dev/null
+++ b/.github/security-baseline
@@ -0,0 +1,3 @@
+# Security scan baseline (keel-linux/.github, security-scan.yml): findings
+# that were read and are not a risk, one per line, the fingerprint and why.
+shellcheck:SC2034:docs/infra/keel-provision.pending:929ba114f93a shell lint, not a security risk: a variable read by a sourcing script or left unused
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
new file mode 100644
index 0000000..6623d98
--- /dev/null
+++ b/.github/workflows/security.yml
@@ -0,0 +1,19 @@
+# Security scanning (keel-linux/.github, profile/WORKFLOWS.md "Security
+# scanning"): gitleaks, bandit, semgrep and shellcheck on GitHub-hosted
+# runners, no secrets. Findings that are not a risk are listed, each with its
+# justification, in .github/security-baseline; gitleaks fixtures, if any, in
+# .github/gitleaks.toml.
+name: security
+on:
+  pull_request:
+  push:
+    branches: [main]
+  workflow_dispatch:
+permissions:
+  contents: read
+jobs:
+  security:
+    uses: keel-linux/.github/.github/workflows/security-scan.yml@main
+    permissions:
+      contents: read
+      security-events: write