diff --git a/internal/check-cdn-pins.mjs b/internal/check-cdn-pins.mjs
new file mode 100644
index 000000000..20ff43da6
--- /dev/null
+++ b/internal/check-cdn-pins.mjs
@@ -0,0 +1,57 @@
+#!/usr/bin/env node
+/**
+ * check-cdn-pins — every runtime third-party script/stylesheet is an EXACT version with an integrity hash.
+ *
+ * CRITIC-5 (2026-09-26): maplibre-gl@5 and maplibre-gl-geocoder@1 were floating ranges, and no runtime
+ * loader set `integrity`, so a CDN could serve any bytes to every partner's visitors unnoticed.
+ * library/constants/cdn.js is now the one registry; loaders set integrity + crossorigin from it.
+ *
+ * OFFLINE (default, in gates:post): in shipped code (library/, plugin-designs/ except scripts/,
+ *   internal/generate-tree.mjs) no jsDelivr/unpkg/esm.sh/api.mapbox.com JS or CSS URL is a floating
+ *   range (@7, @1.2, latest), and every such URL is either in the registry or on the reviewed list below.
+ * --online: also re-fetches every registry URL and requires its sha384 to equal the pinned hash.
+ * EXIT 0 pass · 1 fail · 75 (online) network unavailable
+ */
+import { execFileSync } from 'node:child_process'
+import { createHash } from 'node:crypto'
+import { resolve, dirname } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { CDN } from '../library/constants/cdn.js'
+
+const ROOT = resolve(dirname(fileURLToPath(import.meta.url)), '..')
+const ONLINE = process.argv.includes('--online')
+// Loaded through something other than a <script>/<link> tag, so integrity cannot apply; pinned exactly.
+const REVIEWED = new Map([
+  ['https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-rtl-text/v0.3.0/mapbox-gl-rtl-text.js', 'fetched by the engine (setRTLTextPlugin)'],
+  ['https://cdn.jsdelivr.net/npm/@mapbox/mapbox-gl-rtl-text@0.3.0/dist/mapbox-gl-rtl-text.js', 'fetched by the engine (setRTLTextPlugin)'],
+])
+const known = new Set(Object.values(CDN).map((e) => e.url))
+const URL_RE = /https:\/\/(?:cdn\.jsdelivr\.net|unpkg\.com|esm\.sh|api\.mapbox\.com\/mapbox-gl-js)\/[^\s'"`)<>]+?\.(?:m?js|css)\b/g
+const FLOATING = /@(?:\d+|\d+\.\d+|latest|next)\/|@\^|@~/
+
+const files = execFileSync('git', ['ls-files', '--', 'library', 'plugin-designs', 'internal/generate-tree.mjs'], { cwd: ROOT, encoding: 'utf8' })
+  .split('\n').filter((f) => /\.(m?js|vue|html)$/.test(f) && !/\/scripts\//.test(f) && !/\/index\.html$/.test(f) && !/^plugin-designs\/[^/]+\/data\//.test(f))
+let bad = 0
+const seen = new Map()
+for (const f of files) {
+  const src = execFileSync('git', ['show', `HEAD:${f}`], { cwd: ROOT, encoding: 'utf8', maxBuffer: 64 << 20 })
+  for (const m of src.matchAll(URL_RE)) {
+    const u = m[0]
+    if (!seen.has(u)) seen.set(u, f)
+    if (FLOATING.test(u)) { bad++; console.log(`  FAIL  ${f}: floating version ${u}`) }
+    else if (!known.has(u) && !REVIEWED.has(u)) { bad++; console.log(`  FAIL  ${f}: not in library/constants/cdn.js (no integrity): ${u}`) }
+  }
+}
+console.log(`CDN-PINS: ${seen.size} distinct runtime CDN url(s) in shipped code; registry holds ${known.size}.`)
+if (ONLINE) {
+  for (const [k, e] of Object.entries(CDN)) {
+    let got = ''
+    try { const r = await fetch(e.url); if (!r.ok) throw new Error('HTTP ' + r.status); got = 'sha384-' + createHash('sha384').update(Buffer.from(await r.arrayBuffer())).digest('base64') }
+    catch (err) { console.log(`CDN-PINS: NOT MEASURED — ${e.url}: ${err.message}`); process.exit(75) }
+    const ok = got === e.integrity
+    if (!ok) bad++
+    console.log(`  ${ok ? 'ok  ' : 'FAIL'}  ${k}: ${ok ? 'bytes match the pinned hash' : `served ${got}, pinned ${e.integrity}`}`)
+  }
+}
+if (bad) { console.log(`CDN-PINS: FAIL — ${bad} problem(s).`); process.exit(1) }
+console.log(`CDN-PINS: PASS — every runtime CDN script/stylesheet is an exact version${ONLINE ? ', and every pinned hash matches what the CDN serves' : ' with an integrity hash'}.`)
diff --git a/internal/generate-tree.mjs b/internal/generate-tree.mjs
index e13184465..379e8811d 100644
--- a/internal/generate-tree.mjs
+++ b/internal/generate-tree.mjs
@@ -30,6 +30,7 @@
  * Run standalone:  bun generate-tree.mjs    (expects vite build already ran)
  * Wired into:      bun run build            (runs after the per-bundle vite builds)
  */
+import { CDN } from '../library/constants/cdn.js'
 import {
   readFileSync, writeFileSync, readdirSync, existsSync, mkdirSync, statSync,
   cpSync, rmSync, mkdtempSync,
@@ -167,15 +168,7 @@ const SCAFFOLD_BUNDLES = ['template-bundle']
 // ★ THE MAPBOX ENGINE URL, read from the ONE place that loads it (useMapInstance.js ENGINES.mapbox.js),
 // so the embed snippet's preload can never point at a different version than the one the bundle
 // requests — a mismatched preload is not used, and the engine would download twice.
-const MAPBOX_GL_JS = (() => {
-  try {
-    const src = readFileSync(resolve(__dirname, '..', 'library', 'composables', 'useMapInstance.js'), 'utf8')
-    const m = src.match(/mapbox:\s*\{[^}]*?js:\s*'([^']+mapbox-gl\.js)'/)
-    if (m) return m[1]
-  } catch { /* fall through */ }
-  console.warn('[generate-tree] could not read the Mapbox engine URL from useMapInstance.js; embed snippets get no preload')
-  return ''
-})()
+const MAPBOX_GL_JS = CDN.mapboxGlJs.url   // the ONE registry the bundle's loader reads too (library/constants/cdn.js)
 
 const isBundleDir = (name) => !name.startsWith('_') && !name.startsWith('.') && !DEST_CONFIG.gatedProfiles.includes(name) && !SCAFFOLD_BUNDLES.includes(name)
 
@@ -807,8 +800,8 @@ function mapPageHtml(opts) {
     ? `<!-- MapLibre peer (token-free engine) loaded ONCE here; the custom element
        uses window.maplibregl directly (same versions as @map/composables/useMapInstance). -->
   <link rel="preconnect" href="https://cdn.jsdelivr.net" crossorigin />
-  <link href="https://cdn.jsdelivr.net/npm/maplibre-gl@5/dist/maplibre-gl.css" rel="stylesheet" />
-  <script src="https://cdn.jsdelivr.net/npm/maplibre-gl@5/dist/maplibre-gl.js"></script>`
+  <link href="${CDN.maplibreGlCss.url}" rel="stylesheet" integrity="${CDN.maplibreGlCss.integrity}" crossorigin="anonymous" />
+  <script src="${CDN.maplibreGlJs.url}" integrity="${CDN.maplibreGlJs.integrity}" crossorigin="anonymous"></script>`
     : `<!-- NO STATIC ENGINE TAGS (2026-09-25). This leaf used to hard-link mapbox-gl.css, the
        geocoder css, mapbox-gl.js and the geocoder js from Mapbox's CDN, chosen at BUILD time —
        so a partner embedding it with ?provider=maplibre still sent every visitor's IP to Mapbox
@@ -1306,15 +1299,14 @@ function scanBundles() {
         // pastes this snippet has no leaf page to fetch mapbox-gl.js, so the bundle requested it only
         // after it had downloaded, run and mounted: doxa-simple-map's engine started at 1.06 s, right
         // after its bundle (0.99 s); regions-mfe's at 2.67 s. A preload lets the ~480 KB engine download
-        // alongside the bundle. NO crossorigin attribute, on purpose: ensureEngineScript injects a plain
-        // <script src>, and a preload is only reused when its request mode matches — with crossorigin it
-        // would download twice. Mapbox only: a non-map profile gets none, and a partner switching to
+        // alongside the bundle. It carries crossorigin + integrity because ensureEngineScript's <script> now
+        // does too (library/constants/cdn.js): a preload is reused only when its request mode matches. Mapbox only: a non-map profile gets none, and a partner switching to
         // provider:"maplibre" is told to drop the line, since that engine must make zero Mapbox requests.
         // The default engine is 'auto' (Mapbox only with a token), so a partner with no token drops it too.
         embed: {
           iframe: iframeEmbed,
           script: isMap && MAPBOX_GL_JS
-            ? `<!-- Mapbox engine, fetched early. Keep it only with a real Mapbox token in "tk": without one (or with "provider":"maplibre") the map draws with MapLibre and this line must go -->\n<link rel="preload" as="script" href="${MAPBOX_GL_JS}">\n` + scriptEmbed
+            ? `<!-- Mapbox engine, fetched early. Keep it only with a real Mapbox token in "tk": without one (or with "provider":"maplibre") the map draws with MapLibre and this line must go -->\n<link rel="preload" as="script" href="${MAPBOX_GL_JS}" integrity="${CDN.mapboxGlJs.integrity}" crossorigin="anonymous">\n` + scriptEmbed
             : scriptEmbed,
         },
         ...(instances.length ? { instances } : {}),
diff --git a/library/components/map-controls/GeocoderComponent.vue b/library/components/map-controls/GeocoderComponent.vue
index 08388ff66..0df933cc5 100644
--- a/library/components/map-controls/GeocoderComponent.vue
+++ b/library/components/map-controls/GeocoderComponent.vue
@@ -62,6 +62,7 @@
     geocoder       — the raw MapboxGeocoder instance (for advanced usage)
 -->
 <script setup>
+import { CDN, pinElement } from '@map/constants/cdn.js'
 import { ref, shallowRef, onMounted, onBeforeUnmount, computed, inject, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useEntitySearch } from '../../composables/useSearch.js'
@@ -380,16 +381,16 @@ const standaloneContainer = ref(null)
 // the document head has no effect because the widget renders inside a
 // ShadowRoot. We target the closest ShadowRoot of the map container.
 const GEOCODER_CSS = {
-  mapbox:   'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.css',
-  maplibre: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1/dist/maplibre-gl-geocoder.css',
+  mapbox:   CDN.mapboxGeocoderCss.url,
+  maplibre: CDN.maplibreGeocoderCss.url,
 }
 // MaplibreGeocoder ships as a CDN global (UMD). Mapbox's is preloaded via
 // index.html; MapLibre's is injected on demand so a profile can flip provider
 // with no host change.
-const MAPLIBRE_GEOCODER_JS = 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1/dist/maplibre-gl-geocoder.min.js'
+const MAPLIBRE_GEOCODER_JS = CDN.maplibreGeocoderJs.url   // exact version + SRI: library/constants/cdn.js
 // Same version the generated leaf pages preload, so an on-demand load and a preload cannot end up
 // on two different geocoders.
-const MAPBOX_GEOCODER_JS = 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.min.js'
+const MAPBOX_GEOCODER_JS = CDN.mapboxGeocoderJs.url
 
 function injectGeocoderCSS(shadowRoot, prov) {
   const HREF = GEOCODER_CSS[prov] || GEOCODER_CSS.mapbox
@@ -397,6 +398,7 @@ function injectGeocoderCSS(shadowRoot, prov) {
   const link = document.createElement('link')
   link.rel = 'stylesheet'
   link.href = HREF
+  pinElement(link, HREF)
   shadowRoot.prepend(link)
 }
 
@@ -433,6 +435,7 @@ async function ensureGeocoderScript(src, globalName) {
   await new Promise((resolve) => {
     const el = document.createElement('script')
     el.src = src
+    pinElement(el, src)
     el.async = true
     // Resolve on error too: a blocked CDN must leave the map usable and the bar absent, which is
     // what happened before this existed — never a hang or an unhandled rejection.
diff --git a/library/composables/useMapInstance.js b/library/composables/useMapInstance.js
index 2739c12d2..106d79a58 100644
--- a/library/composables/useMapInstance.js
+++ b/library/composables/useMapInstance.js
@@ -32,17 +32,10 @@ import { useEdgeScrollAffordance } from './useEdgeScrollAffordance.js'
 // The map engine is loaded as a page global (CDN <script>). Profiles / index.html
 // may preload it; if absent we inject it here. Mapbox is the default — its URLs
 // match the existing <script> tags so nothing double-loads or changes.
+// URLs and their integrity hashes come from ONE place (library/constants/cdn.js): exact versions, SRI.
 const ENGINES = {
-  mapbox: {
-    global: 'mapboxgl',
-    js:  'https://api.mapbox.com/mapbox-gl-js/v3.24.0/mapbox-gl.js',
-    css: 'https://api.mapbox.com/mapbox-gl-js/v3.24.0/mapbox-gl.css',
-  },
-  maplibre: {
-    global: 'maplibregl',
-    js:  'https://cdn.jsdelivr.net/npm/maplibre-gl@5/dist/maplibre-gl.js',
-    css: 'https://cdn.jsdelivr.net/npm/maplibre-gl@5/dist/maplibre-gl.css',
-  },
+  mapbox:   { global: 'mapboxgl',   js: CDN.mapboxGlJs.url,   css: CDN.mapboxGlCss.url },
+  maplibre: { global: 'maplibregl', js: CDN.maplibreGlJs.url, css: CDN.maplibreGlCss.url },
 }
 
 // ONE MAPBOX WORDMARK PER PAGE: every map instance renders its own logo, so a
@@ -76,6 +69,7 @@ const OPENFREEMAP_DARK_STYLE = 'https://tiles.openfreemap.org/styles/fiord'
 // 'midnight-glow' / … resolves per engine here; raw URLs pass through.
 import { resolveNamedStyle, applyStylePaint } from '../styles/registry.js'
 import { resolveMapProvider, explicitMapProvider } from './useMapProvider.js'
+import { CDN, pinElement } from '../constants/cdn.js'
 import { installRtlTextPlugin } from '../maps/rtl-text.js'
 import { localizeBasemapLabels } from '../maps/localize-labels.js'
 
@@ -130,6 +124,7 @@ export async function ensureEngineScript(provider) {
     const link = document.createElement('link')
     link.rel = 'stylesheet'
     link.href = cfg.css
+    pinElement(link, cfg.css)
     document.head.appendChild(link)
   }
 
@@ -146,6 +141,7 @@ export async function ensureEngineScript(provider) {
   await new Promise((resolve, reject) => {
     const s = document.createElement('script')
     s.src = cfg.js
+    pinElement(s, cfg.js)
     s.async = false
     s.addEventListener('load',  resolve, { once: true })
     s.addEventListener('error', () => reject(new Error(`[useMapInstance] Failed to load ${provider} engine script`)), { once: true })
@@ -196,6 +192,7 @@ export async function ensureEngineCSS(element, cssUrl) {
   const link = document.createElement('link')
   link.rel  = 'stylesheet'
   link.href = cssUrl
+  pinElement(link, cssUrl)
 
   await Promise.race([
     new Promise(resolve => {
diff --git a/library/constants/cdn.js b/library/constants/cdn.js
new file mode 100644
index 000000000..d8b2ec825
--- /dev/null
+++ b/library/constants/cdn.js
@@ -0,0 +1,44 @@
+/**
+ * cdn.js — EVERY third-party script and stylesheet a plugin loads at runtime, pinned to an EXACT version
+ * with its Subresource Integrity hash (CRITIC-5, 2026-09-26).
+ *
+ * WHY. Floating ranges (maplibre-gl@5, maplibre-gl-geocoder@1) meant a CDN could serve any future release
+ * to every partner's visitors, and with no integrity attribute nothing would notice a tampered file.
+ * Each entry is loaded with `integrity` + `crossorigin="anonymous"` (every host here answers
+ * Access-Control-Allow-Origin: *, measured), so the browser refuses a file whose bytes differ.
+ *
+ * TO BUMP A VERSION: change the url, recompute the hash, and run check:cdn-pins (it re-fetches every
+ * url and compares):
+ *   curl -sL <url> | openssl dgst -sha384 -binary | openssl base64 -A
+ *
+ * Not here: the RTL text plugin, which the ENGINE fetches (setRTLTextPlugin), not a <script> tag, so
+ * integrity cannot be applied; it is pinned to an exact version in library/maps/rtl-text.js.
+ */
+export const CDN = {
+  mapboxGlJs:  { url: 'https://api.mapbox.com/mapbox-gl-js/v3.24.0/mapbox-gl.js',  integrity: 'sha384-tO0clamXONKwbiz7O6xJpUeyJbTSPugC+xM9clvfFvKTH3i8SmCawHGdf5quMWmZ' },
+  mapboxGlCss: { url: 'https://api.mapbox.com/mapbox-gl-js/v3.24.0/mapbox-gl.css', integrity: 'sha384-rp1X/jJ9MpWPef9OimfXhOaOc4Gzs87yQvF+ajwY6X2H4PTeHNycNlLWiWvj7ehV' },
+  // ⚠ MapLibre stays on 5.x FOR NOW, knowingly: GHSA-jrc7-96c5-q579 (an XSS bypass in DOM.sanitize, reached
+  // through a source's ATTRIBUTION string) affects every release <= 6.4.0, and 6.x is ESM-only (no UMD
+  // `maplibregl` global), so upgrading is a loader migration, not a version bump. Exposure meanwhile:
+  // the attribution strings rendered are those of the fixed basemap styles we configure and our own
+  // sources, none reader- or partner-supplied, and SRI pins these exact bytes. A partner who passes a
+  // style from an untrusted origin is exposed until the 6.x migration (tracked separately) lands.
+  maplibreGlJs:  { url: 'https://cdn.jsdelivr.net/npm/maplibre-gl@5.24.0/dist/maplibre-gl.js',  integrity: 'sha384-5+cfbwT0iiub6VsQAdn6yz16nr6sDiQoHx6tm4O8OVYXHYOxcffFmCJBL0dgdvGp' },
+  maplibreGlCss: { url: 'https://cdn.jsdelivr.net/npm/maplibre-gl@5.24.0/dist/maplibre-gl.css', integrity: 'sha384-uTttxo/aOKbdE5RlD/SPzSDoDmNvGlUYPjONi2MN/b7c9HPSvW07OIuyP7uL6jxK' },
+  mapboxGeocoderJs:  { url: 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.min.js', integrity: 'sha384-Lx9WK8XhZk57czwxt6B6nyaDHB5Ayrcrsu4Fw4bCp/Ot/QLOsUZ0xYqLOpOOSXZw' },
+  mapboxGeocoderCss: { url: 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.css',   integrity: 'sha384-1KNhwJNCQTr0DCi/5/OnQcFytgycxTahxNZaqKbAtqmY8bUhu26qxXqvDGXXwplS' },
+  maplibreGeocoderJs:  { url: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1.9.4/dist/maplibre-gl-geocoder.min.js', integrity: 'sha384-RGV5vfoJd7alk8HE+71IyVfu19ciH1FKA15+AuXs6OeBM2npXrmTPFqG23yMiHXi' },
+  maplibreGeocoderCss: { url: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1.9.4/dist/maplibre-gl-geocoder.css',    integrity: 'sha384-UkDpPApjTpHJHpcJiSNAmbobh30W0/dmt0DoKm4V8CWYRYvQ/Jhd/ijFz0tFdVnH' },
+  // d3 for the PPLR maps and the Wall, which load it themselves (pplrData.js, wallD3.js) and keep it off
+  // window.d3; listed so check:cdn-pins can verify their pin.
+  d3: { url: 'https://cdn.jsdelivr.net/npm/d3@7.9.0/dist/d3.min.js', integrity: 'sha384-CjloA8y00+1SDAUkjs099PVfnY2KmDC2BZnws9kh8D/lX1s46w6EPhpXdqMfjK6i' },
+}
+
+/** Set integrity + crossorigin on a <script>/<link> for a registry entry (no-op for an unknown url). */
+export function pinElement(el, url) {
+  const e = Object.values(CDN).find((x) => x.url === url)
+  if (!e) return el
+  el.integrity = e.integrity
+  el.crossOrigin = 'anonymous'
+  return el
+}
diff --git a/plugin-designs/pplr-data-maps/src/utils/pplrData.js b/plugin-designs/pplr-data-maps/src/utils/pplrData.js
index 78ae2c223..6b4248506 100644
--- a/plugin-designs/pplr-data-maps/src/utils/pplrData.js
+++ b/plugin-designs/pplr-data-maps/src/utils/pplrData.js
@@ -6,6 +6,7 @@
  * which joins the tree's shared assets base (set once by the hub from resolveAssetsBase) with
  * pplr/<file>. The files are derived by ../scripts/build-data.mjs into data/pplr/.
  */
+import { CDN, pinElement } from '@map/constants/cdn.js'
 let base = './assets'
 export function setDataBase(b) { if (b) base = String(b).replace(/\/+$/, '') }
 export function dataUrl(file) { return base + '/pplr/' + file }
@@ -89,12 +90,9 @@ export function loadNames() {
 // the Mapbox plugin under provider=mapbox, MapLibre's under provider=maplibre. A hard-coded Mapbox
 // script made this the only request to api.mapbox.com in the keyless (maplibre) gallery.
 export const GEOCODER = {
-  mapbox:   { js: 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.min.js',
-              css: 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.css',
-              global: 'MapboxGeocoder' },
-  maplibre: { js: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1/dist/maplibre-gl-geocoder.min.js',
-              css: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1/dist/maplibre-gl-geocoder.css',
-              global: 'MaplibreGeocoder' },
+  // Exact versions + integrity, from the one registry (library/constants/cdn.js, CRITIC-5).
+  mapbox:   { js: CDN.mapboxGeocoderJs.url,   css: CDN.mapboxGeocoderCss.url,   global: 'MapboxGeocoder' },
+  maplibre: { js: CDN.maplibreGeocoderJs.url, css: CDN.maplibreGeocoderCss.url, global: 'MaplibreGeocoder' },
 }
 const geocoderPromises = {}
 export function ensureGeocoder(provider = 'mapbox') {
@@ -103,6 +101,7 @@ export function ensureGeocoder(provider = 'mapbox') {
   if (!geocoderPromises[provider]) geocoderPromises[provider] = new Promise((res, rej) => {
     const s = document.createElement('script')
     s.src = g.js
+    pinElement(s, g.js)
     s.onload = () => res(); s.onerror = () => { delete geocoderPromises[provider]; rej(new Error('geocoder failed to load')) }
     document.head.appendChild(s)
   })