diff --git a/VERSION b/VERSION
index 4c77920fd..a4c853ea2 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-6.4.1
+6.4.2
diff --git a/deploy/helm/pulse/Chart.yaml b/deploy/helm/pulse/Chart.yaml
index 55c64b725..95d84e26e 100644
--- a/deploy/helm/pulse/Chart.yaml
+++ b/deploy/helm/pulse/Chart.yaml
@@ -2,9 +2,9 @@ apiVersion: v2
 name: pulse
 description: Helm chart for deploying the Pulse hub and optional Docker, Kubernetes, or OpenShift monitoring agent.
 type: application
-version: 6.4.1
-appVersion: "6.4.1"
-icon: https://raw.githubusercontent.com/rcourtman/Pulse/v6.4.1/docs/images/pulse-logo.svg
+version: 6.4.2
+appVersion: "6.4.2"
+icon: https://raw.githubusercontent.com/rcourtman/Pulse/v6.4.2/docs/images/pulse-logo.svg
 keywords:
   - monitoring
   - proxmox
@@ -32,7 +32,7 @@ annotations:
       description: Smoke tests with kind cluster deployment
   artifacthub.io/links: |
     - name: Documentation
-      url: https://github.com/rcourtman/Pulse/blob/v6.4.1/docs/KUBERNETES.md
+      url: https://github.com/rcourtman/Pulse/blob/v6.4.2/docs/KUBERNETES.md
     - name: Support
       url: https://github.com/rcourtman/Pulse/discussions
   artifacthub.io/maintainers: |
diff --git a/deploy/helm/pulse/README.md b/deploy/helm/pulse/README.md
index 92cfed850..6191c03bc 100644
--- a/deploy/helm/pulse/README.md
+++ b/deploy/helm/pulse/README.md
@@ -1,6 +1,6 @@
 # pulse
 
-![Version: 6.4.1](https://img.shields.io/badge/Version-6.4.1-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 6.4.1](https://img.shields.io/badge/AppVersion-6.4.1-informational?style=flat-square)
+![Version: 6.4.2](https://img.shields.io/badge/Version-6.4.2-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 6.4.2](https://img.shields.io/badge/AppVersion-6.4.2-informational?style=flat-square)
 
 Helm chart for deploying the Pulse hub and optional Docker, Kubernetes, or OpenShift monitoring agent.
 
diff --git a/docker-compose.yml b/docker-compose.yml
index 0da9ffb16..82068da8b 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,7 +2,7 @@ version: '3.8'
 
 services:
   pulse:
-    image: ${PULSE_IMAGE:-rcourtman/pulse:6.4.1}
+    image: ${PULSE_IMAGE:-rcourtman/pulse:6.4.2}
     container_name: pulse
     restart: unless-stopped
     logging:
diff --git a/docs/RELEASE_NOTES.md b/docs/RELEASE_NOTES.md
index 392bade3f..450fb505b 100644
--- a/docs/RELEASE_NOTES.md
+++ b/docs/RELEASE_NOTES.md
@@ -7,10 +7,14 @@ For historical v4 notes that previously lived in this repo, see:
 `docs/releases/RELEASE_NOTES_v4.md`
 
 For the current stable v6 packet, see:
+- `docs/releases/RELEASE_NOTES_v6.4.2.md`
+- `docs/releases/V6_CHANGELOG_v6.4.2.md`
+
+For the preceding stable v6 packet, see:
 - `docs/releases/RELEASE_NOTES_v6.4.1.md`
 - `docs/releases/V6_CHANGELOG_v6.4.1.md`
 
-For the preceding stable v6 packet, see:
+For the earlier stable v6 packet, see:
 - `docs/releases/RELEASE_NOTES_v6.4.0.md`
 - `docs/releases/V6_CHANGELOG_v6.4.0.md`
 
diff --git a/docs/UPGRADE_v6.md b/docs/UPGRADE_v6.md
index c60a2acab..89bf62ce4 100644
--- a/docs/UPGRADE_v6.md
+++ b/docs/UPGRADE_v6.md
@@ -4,10 +4,15 @@ This guide covers practical upgrade steps for existing Pulse installs moving to
 
 For the current stable v6 packet, see:
 
+- `docs/releases/RELEASE_NOTES_v6.4.2.md`
+- `docs/releases/V6_CHANGELOG_v6.4.2.md`
+
+For the preceding stable v6 packet, see:
+
 - `docs/releases/RELEASE_NOTES_v6.4.1.md`
 - `docs/releases/V6_CHANGELOG_v6.4.1.md`
 
-For the preceding stable v6 packet, see:
+For the earlier stable v6 packet, see:
 
 - `docs/releases/RELEASE_NOTES_v6.4.0.md`
 - `docs/releases/V6_CHANGELOG_v6.4.0.md`
diff --git a/docs/release-control/v6/internal/subsystems/deployment-installability.md b/docs/release-control/v6/internal/subsystems/deployment-installability.md
index 0b8d71dc3..c1a8e3a3d 100644
--- a/docs/release-control/v6/internal/subsystems/deployment-installability.md
+++ b/docs/release-control/v6/internal/subsystems/deployment-installability.md
@@ -2302,7 +2302,22 @@ version. It opened the `v6.4.0` candidate line from `main` with
 `rollback_version=v6.3.1` and did not move stable/latest install pointers or
 stable semver aliases.
 
-The active stable `v6.4.1` cut sets the repo-root `VERSION`, repo-root
+The active stable `v6.4.2` cut sets the repo-root `VERSION`, repo-root
+`docker-compose.yml` image default, `scripts/install-docker.sh` fallback, and
+Helm chart release metadata to the same `6.4.2` release version. This patch
+release uses the stable hotfix path with `rollback_version=v6.4.1`,
+`hotfix_exception=true`, a release-owner reason, and no fabricated same-version
+RC tag. The governed branch is `main`. The active customer harm is two stable
+authorization failures: authenticated non-administrator organization members
+can reach infrastructure action control, and SSO-only deployments can treat
+every authenticated IdP user as an instance administrator without an explicit
+grant. The exact pushed `main` SHA must pass the integrated candidate checks
+before publication. No governed mobile-facing path changed from `v6.4.1`, so
+the release decision is `no-mobile-impact`. The standing
+SignPath-unavailable policy from `v6.3.2` onward still applies, with public
+Unknown Publisher disclosure and the existing signed integrity controls.
+
+The preceding stable `v6.4.1` cut sets the repo-root `VERSION`, repo-root
 `docker-compose.yml` image default, `scripts/install-docker.sh` fallback, and
 Helm chart release metadata to the same `6.4.1` release version. This patch
 release uses the stable hotfix path with `rollback_version=v6.4.0`,
@@ -2740,13 +2755,15 @@ For the active stable `v6.1.2` cut, the repo-root compose default and
 `scripts/install-docker.sh` fallback must both pin `6.1.2` whenever the
 governed `VERSION` is that stable cut. The stable promotion guard remains in
 force and rejects leftover `-rc.` defaults.
-For the active stable `v6.4.1` cut, the repo-root compose default and
-`scripts/install-docker.sh` fallback must both pin `6.4.1` until the next
+For the active stable `v6.4.2` cut, the repo-root compose default and
+`scripts/install-docker.sh` fallback must both pin `6.4.2` until the next
 governed release moves them forward. The stable promotion guard remains in
 force and rejects leftover `-rc.` defaults. Each new release moves
 these two pins together with the repo-root `VERSION` and the Helm chart metadata
 in the same commit; a cut that leaves any of the four on a superseded value is a
 release-packet blocker.
+For the preceding stable `v6.4.1` cut, the repo-root compose default and
+`scripts/install-docker.sh` fallback both pinned `6.4.1`.
 For the preceding stable `v6.4.0` cut, the repo-root compose default and
 `scripts/install-docker.sh` fallback both pinned `6.4.0`.
 For the preceding stable `v6.3.2` cut, the repo-root compose default and
diff --git a/docs/releases/RELEASE_NOTES_v6.4.2.md b/docs/releases/RELEASE_NOTES_v6.4.2.md
new file mode 100644
index 000000000..9d977c535
--- /dev/null
+++ b/docs/releases/RELEASE_NOTES_v6.4.2.md
@@ -0,0 +1,20 @@
+# Pulse v6.4.2 Release Notes
+
+`v6.4.2` is a stable patch release for the Pulse v6 line. It follows stable
+`v6.4.1` and restores explicit administrator boundaries for infrastructure
+actions and SSO-only deployments.
+
+## What's improved
+
+- **Infrastructure actions honor role boundaries** - Browser and proxy users must now be administrators or hold an explicit action permission before they can plan, approve, view, or execute infrastructure actions.
+- **SSO access no longer implies administrator access** - An authenticated SSO user now needs an effective RBAC `admin` grant for administrator routes. Unassigned, `operator`, and `viewer` users remain non-administrative even when no local administrator exists.
+- **SAML allowlists fail closed** - A configured domain or email allowlist now rejects a SAML assertion that omits the email claim instead of bypassing the allowlist.
+
+## Before you upgrade
+
+- Upgrade promptly when Pulse has organization members, proxy-authenticated users, or SSO users who should not administer the instance or control infrastructure.
+- On an SSO-only deployment, map at least one trusted IdP group to the built-in `admin` role before upgrading so an intended administrator retains access.
+- Existing configured local administrators, explicitly authorized RBAC roles, and action-scoped API tokens remain supported.
+- Pulse Mobile remains compatible. This patch does not require a companion mobile release.
+- Windows Unified Agent binaries are not Authenticode-signed while SignPath remains unavailable and may show an Unknown Publisher warning. Verify downloads with the published checksums and detached signatures.
+- The rollback target is stable `v6.4.1`. On systemd and Proxmox LXC installs, use `sudo /bin/update --version v6.4.1` to return to the previous stable release. For Docker Compose, pin `rcourtman/pulse:6.4.1` and recreate the container.
diff --git a/docs/releases/V6_CHANGELOG_v6.4.2.md b/docs/releases/V6_CHANGELOG_v6.4.2.md
new file mode 100644
index 000000000..54b7ec658
--- /dev/null
+++ b/docs/releases/V6_CHANGELOG_v6.4.2.md
@@ -0,0 +1,50 @@
+# Pulse v6.4.2
+
+_This changelog describes stable `v6.4.2` compared with stable `v6.4.1`._
+
+## Fixed
+
+- The OSS default authorizer no longer treats ordinary authenticated
+  organization membership as permission to use the infrastructure action
+  control plane. Browser and proxy sessions must satisfy the canonical
+  administrator boundary, while explicitly scoped API tokens and real RBAC
+  action grants retain their governed paths.
+- Route and lifecycle guardrails cover planning, review, approval, execution,
+  refresh, and recovery action surfaces so the permission check cannot be
+  bypassed through a sibling action endpoint.
+- SSO authentication no longer becomes instance-administrator authority when
+  no local administrator is configured. SSO browser sessions must carry an
+  effective RBAC `admin` grant on `*` before they can use administrator-only
+  settings, discovery, configuration transfer, platform, or infrastructure
+  action routes.
+- SAML domain and email allowlists now reject assertions without an email
+  claim when either allowlist is configured.
+
+## Upgrade requirement
+
+- An SSO-only installation must map at least one trusted IdP group to the
+  built-in `admin` role before upgrading. Sessions mapped only to `operator`,
+  `viewer`, or no role intentionally lose the administrator access that older
+  versions granted implicitly.
+
+## Release Metadata
+
+- Version: `v6.4.2`
+- Previous stable: `v6.4.1`
+- Rollback target: `v6.4.1`
+- Rollback command: `sudo /bin/update --version v6.4.1`
+- Promotion path: emergency stable patch from `main`, using the single-build
+  release workflow after exact-SHA qualification
+- Emergency reason: current stable releases contain two authorization
+  boundary failures. A non-administrator organization member may reach the
+  infrastructure action control plane, and every authenticated IdP user on an
+  SSO-only instance may inherit instance-administrator authority without an
+  explicit grant
+- Windows signing decision: the standing SignPath-unavailable policy publishes
+  unsigned Windows Unified Agent binaries. They may display an Unknown
+  Publisher warning while exact-SHA candidate binding, checksums, detached
+  signatures, immutable-manifest verification, and published-digest
+  verification remain mandatory
+- Mobile decision: `no-mobile-impact`. The patch changes no governed mobile
+  route, payload, Relay, pairing, approval, push, or onboarding contract, so no
+  companion mobile build or store rollout is required.
diff --git a/frontend-modern/public/docs/UPGRADE_v6.md b/frontend-modern/public/docs/UPGRADE_v6.md
index c60a2acab..89bf62ce4 100644
--- a/frontend-modern/public/docs/UPGRADE_v6.md
+++ b/frontend-modern/public/docs/UPGRADE_v6.md
@@ -4,10 +4,15 @@ This guide covers practical upgrade steps for existing Pulse installs moving to
 
 For the current stable v6 packet, see:
 
+- `docs/releases/RELEASE_NOTES_v6.4.2.md`
+- `docs/releases/V6_CHANGELOG_v6.4.2.md`
+
+For the preceding stable v6 packet, see:
+
 - `docs/releases/RELEASE_NOTES_v6.4.1.md`
 - `docs/releases/V6_CHANGELOG_v6.4.1.md`
 
-For the preceding stable v6 packet, see:
+For the earlier stable v6 packet, see:
 
 - `docs/releases/RELEASE_NOTES_v6.4.0.md`
 - `docs/releases/V6_CHANGELOG_v6.4.0.md`
diff --git a/scripts/install-docker.sh b/scripts/install-docker.sh
index 66bf9d39c..30a75a155 100755
--- a/scripts/install-docker.sh
+++ b/scripts/install-docker.sh
@@ -6,7 +6,7 @@ set -euo pipefail
 
 SCRIPT_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
 DOCKER_IMAGE_REPO="${DOCKER_IMAGE_REPO:-rcourtman/pulse}"
-CANONICAL_DEFAULT_PULSE_VERSION="6.4.1"
+CANONICAL_DEFAULT_PULSE_VERSION="6.4.2"
 
 resolve_default_pulse_version() {
     if [ -n "${PULSE_IMAGE_VERSION:-}" ]; then
diff --git a/scripts/installtests/build_release_assets_test.go b/scripts/installtests/build_release_assets_test.go
index ad6b191b0..25502ff4f 100644
--- a/scripts/installtests/build_release_assets_test.go
+++ b/scripts/installtests/build_release_assets_test.go
@@ -2045,6 +2045,39 @@ func TestDeploymentDefaultsPinVersionedImagesAndHelmDocsChecksum(t *testing.T) {
 	}
 }
 
+func TestV642SecurityPacketCoversBothAdministratorBoundaryFixes(t *testing.T) {
+	notesBytes, err := os.ReadFile(repoFile("docs", "releases", "RELEASE_NOTES_v6.4.2.md"))
+	if err != nil {
+		t.Fatalf("read v6.4.2 release notes: %v", err)
+	}
+	changelogBytes, err := os.ReadFile(repoFile("docs", "releases", "V6_CHANGELOG_v6.4.2.md"))
+	if err != nil {
+		t.Fatalf("read v6.4.2 changelog: %v", err)
+	}
+	notes := string(notesBytes)
+	changelog := string(changelogBytes)
+	for _, required := range []string{
+		"Infrastructure actions honor role boundaries",
+		"SSO access no longer implies administrator access",
+		"map at least one trusted IdP group to the built-in `admin` role before upgrading",
+		"The rollback target is stable `v6.4.1`",
+	} {
+		if !strings.Contains(notes, required) {
+			t.Fatalf("v6.4.2 release notes missing %q", required)
+		}
+	}
+	for _, required := range []string{
+		"effective RBAC `admin` grant on `*`",
+		"SSO-only installation must map at least one trusted IdP group",
+		"Promotion path: emergency stable patch from `main`",
+		"Mobile decision: `no-mobile-impact`",
+	} {
+		if !strings.Contains(changelog, required) {
+			t.Fatalf("v6.4.2 changelog missing %q", required)
+		}
+	}
+}
+
 func TestHelmChartDoesNotPublishRetiredExplorePrepassMonitoring(t *testing.T) {
 	chartDir := repoFile("deploy", "helm", "pulse")
 	err := filepath.WalkDir(chartDir, func(path string, d os.DirEntry, walkErr error) error {
diff --git a/scripts/installtests/install_docker_sh_test.go b/scripts/installtests/install_docker_sh_test.go
index 18239ada2..6de9fee82 100644
--- a/scripts/installtests/install_docker_sh_test.go
+++ b/scripts/installtests/install_docker_sh_test.go
@@ -329,6 +329,13 @@ func TestInstallDockerProofTracksStablePatchReleaseContract(t *testing.T) {
 			"Public Unknown Publisher disclosure",
 		)
 	}
+	if version == "6.4.2" {
+		assertFileContainsAllNormalized(t, repoFile("docs", "release-control", "v6", "internal", "subsystems", "deployment-installability.md"),
+			"The governed branch is `main`",
+			"authenticated non-administrator organization members can reach infrastructure action control",
+			"SSO-only deployments can treat every authenticated IdP user as an instance administrator without an explicit grant",
+		)
+	}
 }
 
 func TestInstallDockerProofTracksStableMinorContract(t *testing.T) {
diff --git a/scripts/release_control/render_release_body_test.py b/scripts/release_control/render_release_body_test.py
index 2e1ca7302..7f7bec47c 100644
--- a/scripts/release_control/render_release_body_test.py
+++ b/scripts/release_control/render_release_body_test.py
@@ -29,6 +29,21 @@ def _discover_rc_draft_packet_paths() -> tuple[str, ...]:
 
 
 class RenderReleaseBodyTest(unittest.TestCase):
+    def test_v642_security_packet_keeps_both_admin_boundaries_visible(self) -> None:
+        notes = (
+            _REPO_ROOT / "docs" / "releases" / "RELEASE_NOTES_v6.4.2.md"
+        ).read_text(encoding="utf-8")
+
+        for expected in (
+            "Infrastructure actions honor role boundaries",
+            "SSO access no longer implies administrator access",
+            "map at least one trusted IdP group to the built-in `admin` role before upgrading",
+            "The rollback target is stable `v6.4.1`",
+        ):
+            self.assertIn(expected, notes)
+        self.assertNotIn("## Fixes", notes)
+        render_release_body.validate_release_notes_shape(notes, "6.4.2")
+
     def test_v640_stable_packet_keeps_release_boundaries_visible(self) -> None:
         notes = (
             _REPO_ROOT / "docs" / "releases" / "RELEASE_NOTES_v6.4.0.md"