diff --git a/ui/src/components/MarkdownBody.test.tsx b/ui/src/components/MarkdownBody.test.tsx
index 3615c501a4..0e8572fbdc 100644
--- a/ui/src/components/MarkdownBody.test.tsx
+++ b/ui/src/components/MarkdownBody.test.tsx
@@ -120,6 +120,33 @@ describe("MarkdownBody", () => {
     expect(html).toContain('alt="Org chart"');
   });
 
+  it("renders decision images as inert references without resolving or preloading them", () => {
+    const resolveImageSrc = vi.fn((src: string) => `https://resolver.invalid/${src}`);
+    const html = renderMarkdown(
+      '# Plan\n\n**Keep this step.**\n\n![Evidence](https://provider.invalid/track.png "Provider image")\n\n![Relative](images/proof.png)\n\n![Protocol relative](//provider.invalid/other.png)',
+      [], { mediaMode: "reference", resolveImageSrc },
+    );
+
+    expect(html).toContain("<h1>Plan</h1>");
+    expect(html).toContain("<strong>Keep this step.</strong>");
+    expect(html).toContain("Image: Evidence (https://provider.invalid/track.png)");
+    expect(html).toContain('title="Provider image"');
+    expect(html).toContain("Image: Relative (images/proof.png)");
+    expect(html).toContain("Image: Protocol relative (//provider.invalid/other.png)");
+    expect(html).not.toMatch(/<(?:img|link|iframe|video|audio)\b/);
+    expect(resolveImageSrc).not.toHaveBeenCalled();
+  });
+
+  it("keeps diagram source inert in decision media mode", () => {
+    const source = 'flowchart LR\n  A@{ img: "https://provider.invalid/diagram.png" }';
+    const html = renderMarkdown(`\`\`\`mermaid\n${source}\n\`\`\``, [], { mediaMode: "reference" });
+
+    expect(html).toContain('class="language-mermaid"');
+    expect(html).toContain("https://provider.invalid/diagram.png");
+    expect(html).not.toContain('class="paperclip-mermaid"');
+    expect(html).not.toContain("Rendering Mermaid diagram");
+  });
+
   it("renders user, agent, project, skill, and routine mentions as chips", () => {
     const html = renderToStaticMarkup(
       <QueryClientProvider client={new QueryClient()}>
diff --git a/ui/src/components/MarkdownBody.tsx b/ui/src/components/MarkdownBody.tsx
index 98c06bf01f..24b9772854 100644
--- a/ui/src/components/MarkdownBody.tsx
+++ b/ui/src/components/MarkdownBody.tsx
@@ -90,6 +90,8 @@ interface MarkdownBodyProps {
   resolveImageSrc?: (src: string) => string | null;
   /** Called when a user clicks an inline image */
   onImageClick?: (src: string) => void;
+  /** Keep untrusted decision media inert: image references and diagram source only. */
+  mediaMode?: "render" | "reference";
   /**
    * Resolver that decides which inline-code workspace file paths may be linked
    * to the issue file viewer. Omitting it (or returning null) leaves every
@@ -719,6 +721,7 @@ function MarkdownBodyImpl({
   externalReferences,
   resolveImageSrc,
   onImageClick,
+  mediaMode = "render",
   resolveWorkspaceFileRef,
 }: MarkdownBodyProps) {
   const { theme } = useTheme();
@@ -803,7 +806,7 @@ function MarkdownBodyImpl({
     ),
     pre: ({ node: _node, children: preChildren, ...preProps }) => {
       const mermaidSource = extractMermaidSource(preChildren);
-      if (mermaidSource) {
+      if (mermaidSource && mediaMode === "render") {
         return <MermaidDiagramBlock source={mermaidSource} darkMode={theme === "dark"} />;
       }
       return <CodeBlock preProps={preProps}>{preChildren}</CodeBlock>;
@@ -914,7 +917,13 @@ function MarkdownBodyImpl({
       );
     },
     };
-    if (resolveImageSrc || onImageClick) {
+    if (mediaMode === "reference") {
+      map.img = ({ src, alt, title }) => (
+        <span data-markdown-image-reference title={title}>
+          Image: {alt || "Untitled image"}{src ? ` (${src})` : ""}
+        </span>
+      );
+    } else if (resolveImageSrc || onImageClick) {
       map.img = ({ node: _node, src, alt, ...imgProps }) => {
         const resolved = resolveImageSrc && src ? resolveImageSrc(src) : null;
         const finalSrc = resolved ?? src;
@@ -930,7 +939,7 @@ function MarkdownBodyImpl({
       };
     }
     return map;
-  }, [theme, linkIssueReferences, linkCaseReferences, externalReferenceLookup, resolveImageSrc, onImageClick]);
+  }, [theme, linkIssueReferences, linkCaseReferences, externalReferenceLookup, resolveImageSrc, onImageClick, mediaMode]);
 
   return (
     <div
diff --git a/ui/src/components/task-chat/QuestionForm.tsx b/ui/src/components/task-chat/QuestionForm.tsx
index 2d5ef3e39f..205231ef03 100644
--- a/ui/src/components/task-chat/QuestionForm.tsx
+++ b/ui/src/components/task-chat/QuestionForm.tsx
@@ -522,7 +522,7 @@ export function QuestionForm({
           tabIndex={0}
           className="mb-3 max-h-96 overflow-auto text-sm text-muted-foreground"
         >
-          <MarkdownBody>{questionSet.description}</MarkdownBody>
+          <MarkdownBody mediaMode="reference">{questionSet.description}</MarkdownBody>
         </div>
       ) : null}
       {question.answerMode === "text" ? (
diff --git a/ui/src/components/task-chat/TaskChatProtocolCard.test.tsx b/ui/src/components/task-chat/TaskChatProtocolCard.test.tsx
index 9af1b59b91..00961fdbaa 100644
--- a/ui/src/components/task-chat/TaskChatProtocolCard.test.tsx
+++ b/ui/src/components/task-chat/TaskChatProtocolCard.test.tsx
@@ -632,6 +632,35 @@ describe("TaskChatProtocolCard", () => {
     expect(container.textContent).toContain("Submitting…");
   });
 
+  it("keeps complete provider plan Markdown while making image references inert", () => {
+    const prefix = '# Release plan\n\n**Preserve every instruction.**\n\n![Evidence](https://provider.invalid/track.png "Provider image")\n\n![Local image](/api/attachments/untrusted/content)\n\n';
+    const suffix = '\n\n```mermaid\nflowchart LR\n  A@{ img: "https://provider.invalid/diagram.png" }\n```\n\nFINAL_PLAN_BOUNDARY';
+    const fullInstructions = "x".repeat(100_000 - prefix.length - suffix.length);
+    const description = prefix + fullInstructions + suffix;
+    expect(description).toHaveLength(100_000);
+    renderCard(root, {
+      id: "provider-plan", kind: "protocol", surface: "runtime_request", runId: "run-1",
+      requestId: "plan-revision-7", requestKind: "runtime", turnId: "turn-1",
+      requestType: "input", status: "pending", prompt: "Review the complete plan.", choices: [], fields: [],
+      questionSet: {
+        schema: "paperclip.question_set.v1", description,
+        questions: [{ id: "decision", prompt: "Accept this plan?", required: true, answerMode: "single_select",
+          options: [{ id: "accept", label: "Accept" }, { id: "reject", label: "Reject" }] }],
+      },
+    });
+
+    const context = container.querySelector('[role="region"][aria-label="Question context"]');
+    expect(context?.querySelector("h1")?.textContent).toBe("Release plan");
+    expect(context?.querySelector("strong")?.textContent).toBe("Preserve every instruction.");
+    expect(context?.textContent).toContain(fullInstructions);
+    expect(context?.textContent).toContain("FINAL_PLAN_BOUNDARY");
+    expect(context?.textContent).toContain("Evidence");
+    expect(context?.textContent).toContain("https://provider.invalid/track.png");
+    expect(context?.querySelector("img, video, audio, iframe, object, embed, image, link")).toBeNull();
+    expect(context?.querySelector('.language-mermaid')?.textContent).toContain('https://provider.invalid/diagram.png');
+    expect(context?.querySelector('.paperclip-mermaid')).toBeNull();
+  });
+
   it("submits the canonical response from a v2 harness question set", async () => {
     const onDecision = vi.fn().mockResolvedValue(undefined);
     renderCard(