diff --git a/packages/cms-admin/src/components/editor/rich-text-editor.tsx b/packages/cms-admin/src/components/editor/rich-text-editor.tsx
index 53e4a836..aa14ca36 100644
--- a/packages/cms-admin/src/components/editor/rich-text-editor.tsx
+++ b/packages/cms-admin/src/components/editor/rich-text-editor.tsx
@@ -20,6 +20,7 @@ import { TextStyle } from "@tiptap/extension-text-style";
 import { Markdown } from "tiptap-markdown";
 import { useEffect, useState, useRef, useCallback } from "react";
 import { cn } from "@/lib/utils";
+import { sanitizeWordPasteHtml } from "@/lib/paste-sanitizer";
 import {
   Tooltip, TooltipContent, TooltipProvider, TooltipTrigger,
 } from "@/components/ui/tooltip";
@@ -2373,10 +2374,10 @@ const SvgEmbed = TipTapNode.create({
 
 /* ─── Toolbar button ─────────────────────────────────────────── */
 function Btn({
-  tooltip, active, disabled, onClick, children,
+  tooltip, active, disabled, onClick, children, testId,
 }: {
   tooltip: string; active?: boolean; disabled?: boolean;
-  onClick: () => void; children: React.ReactNode;
+  onClick: () => void; children: React.ReactNode; testId?: string;
 }) {
   return (
     <Tooltip>
@@ -2384,6 +2385,7 @@ function Btn({
         render={
           <button
             type="button"
+            data-testid={testId}
             onMouseDown={(e) => { e.preventDefault(); onClick(); }}
             disabled={disabled}
             aria-label={tooltip}
@@ -2702,6 +2704,9 @@ function RichTextEditorInner({ value, onChange, disabled, stickyOffset = 132, fe
       onChange(md);
     },
     editorProps: {
+      // F150: strip Word/Office paste cruft before ProseMirror parses, so the
+      // junk never round-trips into stored Markdown (html:true serialiser).
+      transformPastedHTML: (html) => sanitizeWordPasteHtml(html),
       attributes: {
         class: "rte outline-none min-h-[120px]",
         // Block browser extensions (Grammarly, spell-checkers) from injecting
@@ -3154,6 +3159,13 @@ function RichTextEditorInner({ value, onChange, disabled, stickyOffset = 132, fe
               <IconSubscript />
             </Btn>}
 
+            {/* F150: strip all formatting from the selection (inline marks + block type) */}
+            {(has("bold") || has("italic") || has("strike") || has("code")) && <Btn
+              tooltip="Clear formatting" testId="clear-formatting-button"
+              onClick={() => editor.chain().focus().unsetAllMarks().clearNodes().run()}>
+              <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M4 7V4h16v3"/><path d="M5 20h6"/><path d="M13 4 8 20"/><path d="m15 15 5 5"/><path d="m20 15-5 5"/></svg>
+            </Btn>}
+
             {(has("bold") || has("italic") || has("strike") || has("code")) && <Sep />}
 
             {has("bulletList") && <Btn tooltip="Bullet list" active={toolbarState?.isBulletList ?? false}
diff --git a/packages/cms-admin/src/lib/__tests__/paste-sanitizer.test.ts b/packages/cms-admin/src/lib/__tests__/paste-sanitizer.test.ts
new file mode 100644
index 00000000..61096b76
--- /dev/null
+++ b/packages/cms-admin/src/lib/__tests__/paste-sanitizer.test.ts
@@ -0,0 +1,98 @@
+import { describe, it, expect } from "vitest";
+import { sanitizeWordPasteHtml } from "../paste-sanitizer";
+
+describe("sanitizeWordPasteHtml — F150 Word/Office paste cleanup", () => {
+  it("unwraps the sanneandersen span-wrapped markdown, preserving inner markdown", () => {
+    // Ground-truth payload pattern from prod (products/fordjelsen.json).
+    const input =
+      "<span>*Undervisning hjemme hos dig selv via Zoom.*</span>\n\n" +
+      "<span>**<u>1. En sund – og god forløjelse – er grundlaget for al liv.</u>**</span>";
+    const out = sanitizeWordPasteHtml(input);
+    expect(out).not.toContain("<span>");
+    expect(out).not.toContain("</span>");
+    // inner markdown + intentional <u> survive intact
+    expect(out).toContain("*Undervisning hjemme hos dig selv via Zoom.*");
+    expect(out).toContain("**<u>1. En sund");
+    expect(out).toContain("</u>**");
+  });
+
+  it("removes XML-namespace tags like <o:p>", () => {
+    expect(sanitizeWordPasteHtml("<p>hi<o:p></o:p></p>")).toBe("<p>hi</p>");
+    expect(sanitizeWordPasteHtml("<o:p>keep</o:p>")).toBe("keep");
+  });
+
+  it("unwraps <font> tags but keeps their content", () => {
+    expect(sanitizeWordPasteHtml('<font face="Arial" size="3">hello</font>')).toBe("hello");
+  });
+
+  it("strips Office conditional comments and fragment markers", () => {
+    const input =
+      "<!--[if gte mso 9]><xml><o:OfficeDocumentSettings/></xml><![endif]-->" +
+      "<!--StartFragment-->text<!--EndFragment-->";
+    expect(sanitizeWordPasteHtml(input)).toBe("text");
+  });
+
+  it("strips downlevel-revealed conditional comments", () => {
+    expect(sanitizeWordPasteHtml("<![if !mso]>x<![endif]>")).toBe("x");
+  });
+
+  it("removes mso-* style declarations but keeps real ones", () => {
+    const out = sanitizeWordPasteHtml('<p style="margin:0; mso-pagination:none">x</p>');
+    expect(out).toBe('<p style="margin:0">x</p>');
+  });
+
+  it("drops a style attribute that becomes empty after mso stripping, then unwraps the bare span", () => {
+    const out = sanitizeWordPasteHtml('<span style="mso-fareast-language:DA">x</span>');
+    expect(out).toBe("x");
+  });
+
+  it('removes class="Mso…" attributes', () => {
+    expect(sanitizeWordPasteHtml('<p class="MsoNormal">x</p>')).toBe("<p>x</p>");
+  });
+
+  it("drops Word <style> and <xml> blocks wholesale", () => {
+    const input = "<style>p{mso-x:1}</style><xml><w:WordDocument/></xml><p>body</p>";
+    expect(sanitizeWordPasteHtml(input)).toBe("<p>body</p>");
+  });
+
+  // ── edge guards: never destroy intent ──
+
+  it("preserves a deliberate color span (TextStyle/Color)", () => {
+    const input = '<span style="color:#f00">red</span>';
+    expect(sanitizeWordPasteHtml(input)).toBe(input);
+  });
+
+  it("preserves a background-color span", () => {
+    const input = '<span style="background-color:#ff0">hi</span>';
+    expect(sanitizeWordPasteHtml(input)).toBe(input);
+  });
+
+  it("preserves a color span even when it also carried mso noise", () => {
+    const out = sanitizeWordPasteHtml('<span style="mso-x:1; color:#0f0">g</span>');
+    expect(out).toBe('<span style="color:#0f0">g</span>');
+  });
+
+  it("preserves spans with a real class/id/data attribute", () => {
+    expect(sanitizeWordPasteHtml('<span class="badge">x</span>')).toBe('<span class="badge">x</span>');
+    expect(sanitizeWordPasteHtml('<span data-foo="1">x</span>')).toBe('<span data-foo="1">x</span>');
+  });
+
+  it("leaves clean third-party HTML untouched", () => {
+    const input = '<strong>bold</strong> and <a href="https://x.com">link</a><ul><li>a</li><li>b</li></ul>';
+    expect(sanitizeWordPasteHtml(input)).toBe(input);
+  });
+
+  it("returns empty and plain input unchanged", () => {
+    expect(sanitizeWordPasteHtml("")).toBe("");
+    expect(sanitizeWordPasteHtml("just text")).toBe("just text");
+  });
+
+  it("fully unwraps nested noise-only spans", () => {
+    expect(sanitizeWordPasteHtml("<span><span>deep</span></span>")).toBe("deep");
+  });
+
+  it("keeps a semantic color span while unwrapping a noise span around it", () => {
+    const out = sanitizeWordPasteHtml('<span><span style="color:#f00">red</span></span>');
+    expect(out).toBe('<span style="color:#f00">red</span>');
+  });
+});
diff --git a/packages/cms-admin/src/lib/paste-sanitizer.ts b/packages/cms-admin/src/lib/paste-sanitizer.ts
new file mode 100644
index 00000000..d5d2a8ef
--- /dev/null
+++ b/packages/cms-admin/src/lib/paste-sanitizer.ts
@@ -0,0 +1,109 @@
+/**
+ * F150 — Paste formatting sanitization.
+ *
+ * Strips Microsoft Word / Office clipboard cruft from pasted HTML *before*
+ * ProseMirror parses it, so the junk never reaches the editor schema and never
+ * round-trips into stored Markdown (the editor serialises with `html: true`,
+ * which otherwise re-emits leftover inline wrappers as literal `<span>` text on
+ * public sites — the sanneandersen "fordjelsen" bug).
+ *
+ * Pure string transform on purpose: no DOM dependency, so it runs unchanged in
+ * the browser paste path AND is unit-testable under the repo's `node` vitest env.
+ *
+ * What it removes:
+ *  - Office conditional comments + all HTML comments (StartFragment/EndFragment)
+ *  - `<style>` / `<xml>` blocks Word injects
+ *  - XML-namespace tags: `<o:p>`, `<w:…>`, `<m:…>`, `<v:…>`, `<st1:…>`, …
+ *  - `<font>` tags (unwrapped — content kept)
+ *  - `mso-*` declarations inside `style=""` (and the attribute if it empties)
+ *  - `class="Mso…"` attributes
+ *  - noise-only `<span>` wrappers (unwrapped — content kept)
+ *
+ * What it preserves:
+ *  - all real content + intentional inline markup (`<u>`, `<strong>`, `<a>`, …)
+ *  - spans that carry a deliberate `color`/`background-color` (TextStyle/Color),
+ *    or a real `class`/`id`/`data-*` attribute
+ */
+
+/** Remove `mso-*` declarations from a CSS string; return the cleaned remainder. */
+function stripMsoFromCss(css: string): string {
+  return css
+    .split(";")
+    .map((d) => d.trim())
+    .filter((d) => d.length > 0)
+    .filter((d) => !/^mso-/i.test(d.split(":")[0].trim()))
+    .join("; ");
+}
+
+/** True if a span's attribute string carries something worth keeping the span for. */
+function spanIsSemantic(attrs: string): boolean {
+  // a deliberate colour (covers `color:` and `background-color:`)
+  if (/\bcolor\s*:/i.test(attrs)) return true;
+  // a real structural attribute another feature may rely on
+  if (/\s(?:class|id|data-[\w-]+)\s*=/i.test(attrs)) return true;
+  return false;
+}
+
+/** Unwrap noise-only `<span>` wrappers from innermost out, keeping semantic ones. */
+function unwrapNoiseSpans(html: string): string {
+  // Match an innermost span (its content holds no further `<span` opening).
+  const innermost = /<span((?:\s[^>]*)?)>((?:(?!<span)[\s\S])*?)<\/span>/i;
+  let out = html;
+  let prev = "";
+  let guard = 0;
+  while (out !== prev && guard < 100) {
+    prev = out;
+    out = out.replace(innermost, (_m, attrs: string, inner: string) =>
+      spanIsSemantic(attrs)
+        ? // park kept spans under a placeholder so the loop can't re-match them
+          `<keptspan${attrs}>${inner}</keptspan>`
+        : inner,
+    );
+    guard++;
+  }
+  // restore parked spans
+  return out.replace(/<keptspan/gi, "<span").replace(/<\/keptspan>/gi, "</span>");
+}
+
+/**
+ * Sanitise pasted HTML, removing Word/Office cruft while preserving real
+ * content and intentional formatting. Safe to call on any pasted HTML.
+ */
+export function sanitizeWordPasteHtml(html: string): string {
+  if (!html) return html;
+  // Quick exit: nothing that looks like Office cruft → return untouched.
+  if (!/<(?:o|w|m|v|st1|x):|<font\b|mso-|class=["']?Mso|<span\b|<!--|<!\[|<style\b|<xml\b/i.test(html)) {
+    return html;
+  }
+
+  let out = html;
+
+  // 1. Drop `<style>` and `<xml>` blocks Word injects wholesale.
+  out = out.replace(/<style\b[\s\S]*?<\/style>/gi, "");
+  out = out.replace(/<xml\b[\s\S]*?<\/xml>/gi, "");
+
+  // 2. Drop all HTML comments (incl. Office conditional `<!--[if …]>…<![endif]-->`
+  //    and StartFragment/EndFragment markers) + downlevel-revealed `<![if]>` forms.
+  out = out.replace(/<!--[\s\S]*?-->/g, "");
+  out = out.replace(/<!\[(?:end)?if[^\]]*\]>/gi, "");
+
+  // 3. Drop XML-namespace tags (`<o:p>`, `<w:…>`, …) — open + close, keep content.
+  out = out.replace(/<\/?[a-z]+:[^>]*>/gi, "");
+
+  // 4. Unwrap `<font …>` tags — keep their content.
+  out = out.replace(/<\/?font\b[^>]*>/gi, "");
+
+  // 5. Drop Office-generated `class="Mso…"` attributes.
+  out = out.replace(/\sclass=("|')Mso[^"']*\1/gi, "");
+
+  // 6. Strip `mso-*` declarations from style attributes; drop the attr if empty.
+  out = out.replace(/\sstyle=("|')([\s\S]*?)\1/gi, (_m, _q, css: string) => {
+    const cleaned = stripMsoFromCss(css);
+    return cleaned ? ` style="${cleaned}"` : "";
+  });
+
+  // 7. Unwrap noise-only spans (after step 6 mso-only spans are attribute-less).
+  out = unwrapNoiseSpans(out);
+
+  return out;
+}