diff --git a/src/__tests__/core/sanitize.test.ts b/src/__tests__/core/sanitize.test.ts
index 2d9e1091f..b013fa759 100644
--- a/src/__tests__/core/sanitize.test.ts
+++ b/src/__tests__/core/sanitize.test.ts
@@ -15,7 +15,7 @@
  */
 
 import { describe, it, expect } from 'bun:test'
-import { sanitizeRichtext, isRichtextPropKey, PLAIN_TEXT_CONFIG } from '@core/sanitize'
+import { sanitizeRichtext, sanitizePostBody, isRichtextPropKey, PLAIN_TEXT_CONFIG } from '@core/sanitize'
 
 // ---------------------------------------------------------------------------
 // XSS prevention — the core contract
@@ -230,6 +230,131 @@ describe('sanitizeRichtext() in server runtime', () => {
   })
 })
 
+// ---------------------------------------------------------------------------
+// sanitizePostBody() — 2026-08-13 blog round-2 fix. Post/page body content
+// (base.outlet's markdown-rendered html) needs a wider allowlist than
+// sanitizeRichtext(), including iframe embeds scoped to a trusted-host
+// allowlist. See @core/sanitize POST_BODY_CONFIG.
+// ---------------------------------------------------------------------------
+
+describe('sanitizePostBody() — trusted-host iframe embeds', () => {
+  it('keeps an iframe embed from youtube.com', () => {
+    const result = sanitizePostBody(
+      '<iframe src="https://www.youtube.com/embed/dQw4w9WgXcQ" width="560" height="315" allowfullscreen></iframe>',
+    )
+    expect(result).toContain('<iframe')
+    expect(result).toContain('youtube.com/embed/dQw4w9WgXcQ')
+  })
+
+  it('keeps an iframe embed from youtube-nocookie.com', () => {
+    const result = sanitizePostBody(
+      '<iframe src="https://www.youtube-nocookie.com/embed/dQw4w9WgXcQ"></iframe>',
+    )
+    expect(result).toContain('<iframe')
+    expect(result).toContain('youtube-nocookie.com/embed/dQw4w9WgXcQ')
+  })
+
+  it('keeps a bare (non-www) youtube.com host', () => {
+    const result = sanitizePostBody('<iframe src="https://youtube.com/embed/dQw4w9WgXcQ"></iframe>')
+    expect(result).toContain('<iframe')
+  })
+
+  it('strips an iframe embed from an untrusted host entirely (not just the src)', () => {
+    const result = sanitizePostBody('<iframe src="https://evil.com/phish"></iframe>')
+    expect(result).not.toContain('<iframe')
+    expect(result).not.toContain('evil.com')
+  })
+
+  it('strips an iframe with no src at all', () => {
+    const result = sanitizePostBody('<iframe></iframe>')
+    expect(result).not.toContain('<iframe')
+  })
+
+  it('strips a lookalike host that merely contains "youtube.com" (not a real subdomain)', () => {
+    // e.g. "youtube.com.evil.com" or "evilyoutube.com" must NOT pass a naive
+    // substring check — isTrustedIframeHost requires exact match or a
+    // genuine `.` + trusted-host suffix.
+    const lookalikes = [
+      'https://youtube.com.evil.com/embed/x',
+      'https://evilyoutube.com/embed/x',
+      'https://notyoutube.com/embed/x',
+    ]
+    for (const src of lookalikes) {
+      const result = sanitizePostBody(`<iframe src="${src}"></iframe>`)
+      expect(result).not.toContain('<iframe')
+    }
+  })
+
+  it('strips javascript: and data: iframe src', () => {
+    expect(sanitizePostBody('<iframe src="javascript:alert(1)"></iframe>')).not.toContain('<iframe')
+    expect(sanitizePostBody('<iframe src="data:text/html,<script>alert(1)</script>"></iframe>')).not.toContain('<iframe')
+  })
+
+  it('still strips <script> tags and event-handler attributes (iframe allowlisting is not a blanket HTML-open)', () => {
+    const result = sanitizePostBody('<p onclick="alert(1)">hi</p><script>alert(2)</script>')
+    expect(result).not.toContain('onclick')
+    expect(result).not.toContain('<script')
+    expect(result).not.toContain('alert')
+    expect(result).toContain('hi')
+  })
+
+  it('preserves images, tables, and video — the elements a real post body needs that plain richtext strips', () => {
+    const result = sanitizePostBody(
+      '<img src="https://example.com/a.png" alt="a"><table><tbody><tr><td>x</td></tr></tbody></table><video controls src="https://example.com/v.mp4"></video>',
+    )
+    expect(result).toContain('<img')
+    expect(result).toContain('<table')
+    expect(result).toContain('<video')
+  })
+
+  it('preserves a <video poster> with a <source> child — the form real editors/importers emit', () => {
+    // A bare `<video src=…>` is the exception, not the rule: most editors
+    // (Webflow among them) emit `<video controls poster=…><source src=…
+    // type=…></video>` and rely on <source> to carry the actual playable
+    // file. Before `source`/`poster`/`type` were allowlisted this published
+    // as an empty, unplayable `<video controls>`.
+    const result = sanitizePostBody(
+      '<video controls poster="https://example.com/thumb.avif"><source src="https://example.com/clip.mp4" type="video/mp4"></video>',
+    )
+    expect(result).toContain('<video')
+    expect(result).toContain('poster="https://example.com/thumb.avif"')
+    expect(result).toContain('<source')
+    expect(result).toContain('src="https://example.com/clip.mp4"')
+    expect(result).toContain('type="video/mp4"')
+  })
+
+  it('preserves playsinline, loop, muted, and preload on <video>', () => {
+    const result = sanitizePostBody(
+      '<video controls playsinline loop muted preload="auto" src="https://example.com/v.mp4"></video>',
+    )
+    expect(result).toContain('playsinline')
+    expect(result).toContain('loop')
+    expect(result).toContain('muted')
+    expect(result).toContain('preload="auto"')
+  })
+
+  it('preserves figure/figcaption — the wrapper rich-text editors put around images', () => {
+    const result = sanitizePostBody(
+      '<figure><img src="https://example.com/a.png" alt="a"><figcaption>A caption</figcaption></figure>',
+    )
+    expect(result).toContain('<figure')
+    expect(result).toContain('<figcaption')
+    expect(result).toContain('A caption')
+  })
+
+  it('preserves the same safe formatting tags sanitizeRichtext does', () => {
+    const result = sanitizePostBody('<p><strong>Bold</strong> <em>italic</em> <a href="https://example.com">link</a></p>')
+    expect(result).toContain('<strong>Bold</strong>')
+    expect(result).toContain('<em>italic</em>')
+    expect(result).toContain('rel="noopener noreferrer"')
+  })
+
+  it('plain sanitizeRichtext() (used by every OTHER richtext field) still strips iframe — confirms the wider allowlist is scoped to post-body only', () => {
+    const result = sanitizeRichtext('<iframe src="https://www.youtube.com/embed/dQw4w9WgXcQ"></iframe>')
+    expect(result).not.toContain('<iframe')
+  })
+})
+
 // ---------------------------------------------------------------------------
 // isRichtextPropKey — prop key detection
 // ---------------------------------------------------------------------------
diff --git a/src/__tests__/publisher/outletEntryBody.test.ts b/src/__tests__/publisher/outletEntryBody.test.ts
index d53f8be96..8f52d8912 100644
--- a/src/__tests__/publisher/outletEntryBody.test.ts
+++ b/src/__tests__/publisher/outletEntryBody.test.ts
@@ -17,11 +17,11 @@ const bodyModule = makeModule('base.body', {
   render: (_props, children) => ({ html: `<main>${children.join('')}</main>` }),
 })
 
-// Mirrors the real base.outlet render: a hidden richtext `html` prop (so
-// `escapeProps` sanitises rather than HTML-escapes it) emitted inside the
-// content-region marker.
+// Mirrors the real base.outlet render: a hidden richtextBody `html` prop (so
+// `escapeProps` sanitises via the wider POST_BODY_CONFIG rather than
+// HTML-escaping it) emitted inside the content-region marker.
 const outletModule = makeModule('base.outlet', {
-  schema: { html: { type: 'richtext', label: 'Content', hidden: true } },
+  schema: { html: { type: 'richtextBody', label: 'Content', hidden: true } },
   render: (props) => ({
     html: `<section data-instatic-content-region>${String((props as { html?: string }).html ?? '')}</section>`,
   }),
@@ -66,4 +66,51 @@ describe('entry outlet body binding', () => {
     expect(html).toContain('data-instatic-content-region')
     expect(html).not.toContain('Hello world')
   })
+
+  // 2026-08-13 blog round-2 regression: a raw <iframe> YouTube embed pasted
+  // into a post's markdown body (the CMS has no @[video]-style syntax for
+  // iframe embeds — authors paste the platform's real embed HTML) was being
+  // silently stripped by the outlet's sanitizer end-to-end. This is the same
+  // path the real blog posts hit: markdown body -> renderMarkdownToHtml
+  // (passes raw HTML blocks through untouched) -> escapeProps ->
+  // sanitizePostBody (trusted-host allowlist, not a blanket strip).
+  it('renders a YouTube iframe embed pasted into the entry body, end-to-end', () => {
+    const page = makePage({
+      root: { moduleId: 'base.body', children: ['outlet'] },
+      outlet: { moduleId: 'base.outlet' },
+    })
+
+    const body = [
+      '## How to Run MCP Servers',
+      '',
+      '<iframe src="https://www.youtube.com/embed/dQw4w9WgXcQ" width="560" height="315" allowfullscreen></iframe>',
+      '',
+      'More text after the embed.',
+    ].join('\n')
+
+    const { html } = publishPage(page, makeSite(), registry, {
+      templateContext: { entryStack: [entry(body)] },
+    })
+
+    expect(html).toContain('<iframe')
+    expect(html).toContain('youtube.com/embed/dQw4w9WgXcQ')
+    expect(html).toContain('More text after the embed.')
+  })
+
+  it('strips an iframe embed from an untrusted host in the entry body, end-to-end', () => {
+    const page = makePage({
+      root: { moduleId: 'base.body', children: ['outlet'] },
+      outlet: { moduleId: 'base.outlet' },
+    })
+
+    const body = '<iframe src="https://evil.com/phish"></iframe>\n\nSafe text.'
+
+    const { html } = publishPage(page, makeSite(), registry, {
+      templateContext: { entryStack: [entry(body)] },
+    })
+
+    expect(html).not.toContain('<iframe')
+    expect(html).not.toContain('evil.com')
+    expect(html).toContain('Safe text.')
+  })
 })
diff --git a/src/admin/shared/DataBindingPicker/bindingCompatibility.ts b/src/admin/shared/DataBindingPicker/bindingCompatibility.ts
index 81db1e20b..0949b4d48 100644
--- a/src/admin/shared/DataBindingPicker/bindingCompatibility.ts
+++ b/src/admin/shared/DataBindingPicker/bindingCompatibility.ts
@@ -44,6 +44,11 @@ export const BINDING_COMPATIBILITY: Record<PropertyControlKind, readonly DataFie
   text:     ['text', 'longText', 'richText', 'url', 'email', 'select', 'multiSelect', 'relation', 'number', 'boolean', 'date', 'dateTime'],
   textarea: ['text', 'longText', 'richText'],
   richtext: ['richText', 'longText', 'text'],
+  // richtextBody is the implicit body-content binding target on base.outlet —
+  // the publisher wires it programmatically (dynamicBindings.ts's
+  // OUTLET_BODY_BINDING), never through this picker, and the control is
+  // `hidden: true` so it never reaches the UI this map serves.
+  richtextBody: [],
   // svg holds raw inline-SVG markup — edited in the code editor, never wired
   // to a data field.
   svg:      [],
diff --git a/src/core/module-engine/propertySchema.ts b/src/core/module-engine/propertySchema.ts
index c71cc6947..7acb9b29a 100644
--- a/src/core/module-engine/propertySchema.ts
+++ b/src/core/module-engine/propertySchema.ts
@@ -162,6 +162,17 @@ export const PropertyControlSchema = Type.Recursive((Self) => Type.Union([
     { ...PropertyControlBaseSchema, type: Type.Literal('richtext') },
     { additionalProperties: false },
   ),
+  Type.Object(
+    // Distinct from `richtext`: full post/page body content rendered from
+    // markdown (base.outlet's `html` binding target), which needs a wider
+    // safe-tag allowlist than short-form richtext fields — images, tables,
+    // and iframe embeds scoped to a trusted-host allowlist (see
+    // `POST_BODY_CONFIG` in `@core/sanitize`). Kept separate from `richtext`
+    // rather than widening that config globally, so every other richtext
+    // field in the CMS (CTA copy, etc.) stays on the narrower default.
+    { ...PropertyControlBaseSchema, type: Type.Literal('richtextBody') },
+    { additionalProperties: false },
+  ),
   Type.Object(
     { ...PropertyControlBaseSchema, type: Type.Literal('svg') },
     { additionalProperties: false },
@@ -208,6 +219,7 @@ const CONTENT_CONTROL_TYPES: ReadonlySet<PropertyControl['type']> = new Set([
   'text',
   'textarea',
   'richtext',
+  'richtextBody',
   'svg',
   'url',
   'image',
diff --git a/src/core/publisher/escapeProps.ts b/src/core/publisher/escapeProps.ts
index 070f38fc3..b05f46e74 100644
--- a/src/core/publisher/escapeProps.ts
+++ b/src/core/publisher/escapeProps.ts
@@ -37,7 +37,7 @@
 
 import type { PropertyControl, PropertySchema } from '@core/module-engine'
 import { escapeHtml, isSafeUrl } from './utils'
-import { sanitizeRichtext, sanitizeSvg } from '@core/sanitize'
+import { sanitizeRichtext, sanitizeSvg, sanitizePostBody } from '@core/sanitize'
 
 /**
  * Resolve the control declared for `key`. Top-level keys are a direct lookup;
@@ -95,6 +95,14 @@ export function escapeProps(
       // sanitizeRichtext falls back to conservative tag stripping only in
       // runtimes that have not installed DOMPurify (for example one-off scripts).
       escaped[key] = sanitizeRichtext(value)
+    } else if (type === 'richtextBody') {
+      // Post/page body content (base.outlet's markdown-rendered `html`):
+      // wider allowlist than plain `richtext` (images, tables, iframe embeds
+      // scoped to a trusted-host allowlist) — see POST_BODY_CONFIG in
+      // @core/sanitize. Kept as its own control type rather than widening
+      // RICHTEXT_CONFIG globally, so short-form richtext fields elsewhere in
+      // the CMS stay on the narrower default.
+      escaped[key] = sanitizePostBody(value)
     } else if (type === 'url' || type === 'image' || type === 'media') {
       // URLs: block javascript: and vbscript: schemes; pass safe URLs through raw
       // so that module render() functions can HTML-escape them via safeUrl() from
diff --git a/src/core/sanitize.ts b/src/core/sanitize.ts
index a365bc01e..1249452ed 100644
--- a/src/core/sanitize.ts
+++ b/src/core/sanitize.ts
@@ -31,12 +31,22 @@ import DOMPurify, { type Config } from 'dompurify'
 
 type DOMPurifyHookNode = {
   tagName?: string
+  getAttribute?: (name: string) => string | null
   setAttribute?: (name: string, value: string) => void
+  remove?: () => void
 }
 
+type DOMPurifySanitizeElementData = { tagName: string; allowedTags: Record<string, boolean> }
+
 export type DOMPurifyRuntime = {
   sanitize?: (value: string, config?: Config) => unknown
-  addHook?: (hookName: 'afterSanitizeAttributes', callback: (node: DOMPurifyHookNode) => void) => void
+  addHook?: {
+    (hookName: 'afterSanitizeAttributes', callback: (node: DOMPurifyHookNode) => void): void
+    (
+      hookName: 'uponSanitizeElement',
+      callback: (node: DOMPurifyHookNode, data: DOMPurifySanitizeElementData) => void,
+    ): void
+  }
 }
 
 type DOMPurifyFactory = DOMPurifyRuntime & ((window: Window) => DOMPurifyRuntime)
@@ -143,6 +153,110 @@ const RICHTEXT_CONFIG: Config = {
   RETURN_DOM_FRAGMENT: false,
 }
 
+/**
+ * Hosts a `<iframe>` in post-body content is allowed to embed. Checked
+ * against the `src` attribute's hostname (case-insensitive, exact match or
+ * subdomain of one of these) by the DOMPurify hook installed below —
+ * everything else has its iframe stripped, script tags and all other
+ * dangerous elements are already excluded by ALLOWED_TAGS regardless of
+ * this list.
+ */
+const TRUSTED_IFRAME_HOSTS = [
+  'youtube.com',
+  'youtube-nocookie.com',
+] as const
+
+function isTrustedIframeHost(hostname: string): boolean {
+  const host = hostname.toLowerCase()
+  return TRUSTED_IFRAME_HOSTS.some((trusted) => host === trusted || host.endsWith(`.${trusted}`))
+}
+
+/**
+ * Post-body config — used for full post/page body content rendered from
+ * markdown (base.outlet's `html` binding, `richtextBody` control type).
+ * Wider than `RICHTEXT_CONFIG`: adds the block-level elements a markdown
+ * body actually produces (images, GFM tables, headings' remaining levels,
+ * horizontal rules, the CMS `@[video](url)` embed) PLUS `iframe`, scoped to
+ * `TRUSTED_IFRAME_HOSTS` via the `uponSanitizeElement` hook below — an
+ * iframe whose `src` host isn't on the allowlist (or is missing/unparsable)
+ * is removed entirely, not just stripped of the offending attribute, since
+ * a same-tag-different-src replacement is exactly what an attacker would
+ * try first.
+ *
+ * `source`, `figure`, and `figcaption` are included because that's the
+ * markup real rich-text editors and importers (Webflow, etc.) actually
+ * emit — a `<video>` wraps its playable file in `<source src=… type=…>`
+ * rather than using `<video src=…>` directly, and images get wrapped in
+ * `<figure>`/`<figcaption>` for captions. Without `source` the tag was
+ * previously dropped, so a `<video controls poster="…"><source src="…"
+ * type="video/mp4"></video>` published as a bare, unplayable `<video
+ * controls>`.
+ */
+const POST_BODY_CONFIG: Config = {
+  ALLOWED_TAGS: [
+    'p', 'br', 'hr',
+    'h1', 'h2', 'h3', 'h4', 'h5', 'h6',
+    'strong', 'b', 'em', 'i', 'u', 's', 'del', 'ins',
+    'a', 'ul', 'ol', 'li',
+    'blockquote', 'code', 'pre',
+    'span', 'div',
+    'img', 'video', 'source', 'figure', 'figcaption',
+    'table', 'thead', 'tbody', 'tr', 'th', 'td',
+    'iframe',
+  ],
+  ALLOWED_ATTR: [
+    'href', 'target', 'rel', 'class', 'id',
+    'src', 'alt', 'title', 'loading', 'controls',
+    'width', 'height', 'frameborder', 'allow', 'allowfullscreen', 'referrerpolicy',
+    'poster', 'type', 'playsinline', 'loop', 'muted', 'preload',
+  ],
+  ADD_ATTR: ['target'],
+  ALLOW_DATA_ATTR: false,
+  NAMESPACE: 'http://www.w3.org/1999/xhtml',
+  RETURN_DOM: false,
+  RETURN_DOM_FRAGMENT: false,
+}
+
+const postBodyPurifiersWithIframeHook = new WeakSet<object>()
+
+function installIframeHostHook(purifier: DOMPurifyRuntime): DOMPurifyRuntime {
+  if (postBodyPurifiersWithIframeHook.has(purifier) || typeof purifier.addHook !== 'function') {
+    return purifier
+  }
+  purifier.addHook('uponSanitizeElement', (node, data) => {
+    if (data.tagName !== 'iframe') return
+    const src = node.getAttribute?.('src') ?? ''
+    let hostname: string
+    try {
+      hostname = new URL(src, 'http://invalid.example').hostname
+    } catch {
+      hostname = ''
+    }
+    if (!src || !isTrustedIframeHost(hostname)) {
+      node.remove?.()
+    }
+  })
+  postBodyPurifiersWithIframeHook.add(purifier)
+  return purifier
+}
+
+/**
+ * Sanitize full post/page body HTML (already markdown-rendered) — the
+ * `richtextBody` control type's escapeProps() path. See `POST_BODY_CONFIG`.
+ */
+export function sanitizePostBody(value: unknown): string {
+  const str = String(value ?? '')
+  if (!str.trim()) return ''
+
+  const purifier = getDOMPurify()
+  if (!purifier || typeof purifier.sanitize !== 'function') {
+    return stripHtmlFallback(str)
+  }
+
+  installIframeHostHook(purifier)
+  return String(purifier.sanitize(str, POST_BODY_CONFIG))
+}
+
 /**
  * Strict config — strips ALL HTML tags; returns plain text only.
  * Use for single-line fields that should never contain markup.
diff --git a/src/modules/base/outlet/index.ts b/src/modules/base/outlet/index.ts
index 47a4b123f..63f56ad36 100644
--- a/src/modules/base/outlet/index.ts
+++ b/src/modules/base/outlet/index.ts
@@ -42,12 +42,14 @@ export const OutletModule: ModuleDefinition<OutletStoredProps> = {
     /**
      * Binding target only — the publisher fills this with the current entry's
      * richtext body (`{currentEntry.body}`) or a bound VC param. Declared as a
-     * hidden richtext control so the publisher's `escapeProps` sanitises it via
-     * DOMPurify (rather than HTML-escaping it, which would entity-encode the
-     * rendered body). `hidden: true` keeps it out of the Properties panel — it
+     * hidden `richtextBody` control (not the narrower `richtext`) so the
+     * publisher's `escapeProps` sanitises it via the wider POST_BODY_CONFIG —
+     * images, tables, and iframe embeds scoped to a trusted-host allowlist,
+     * all of which a real markdown post body needs and plain `richtext`
+     * fields don't. `hidden: true` keeps it out of the Properties panel — it
      * is never hand-edited.
      */
-    html: { type: 'richtext', label: 'Content', hidden: true },
+    html: { type: 'richtextBody', label: 'Content', hidden: true },
   },
 
   propsSchema: OutletPropsSchema,