diff --git a/.changeset/fix-web-image-csp.md b/.changeset/fix-web-image-csp.md
new file mode 100644
index 0000000000..ce769f7377
--- /dev/null
+++ b/.changeset/fix-web-image-csp.md
@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+web: Fix uploaded and persisted images failing to display on non-loopback server connections.
diff --git a/packages/kap-server/src/middleware/securityHeaders.ts b/packages/kap-server/src/middleware/securityHeaders.ts
index 21f27767dd..412218b1a2 100644
--- a/packages/kap-server/src/middleware/securityHeaders.ts
+++ b/packages/kap-server/src/middleware/securityHeaders.ts
@@ -9,8 +9,9 @@
  * Headers:
  *   - `X-Content-Type-Options: nosniff` — stop MIME sniffing.
  *   - `Referrer-Policy: no-referrer` — never leak the URL to third parties.
- *   - `Content-Security-Policy: default-src 'self'` — the bundled Web UI is
- *     same-origin, so `'self'` covers it; tighten later if needed.
+ *   - `Content-Security-Policy` — the bundled Web UI is same-origin. Images
+ *     additionally allow `data:` for persisted base64 content and `blob:` for
+ *     local attachment previews and authenticated media responses.
  *   - `Strict-Transport-Security` — ONLY when `opts.tls === true`. In this
  *     phase TLS is terminated by a reverse proxy (Caddy/nginx), so `start.ts`
  *     passes `tls: false` and HSTS is omitted here; the proxy is responsible
@@ -25,6 +26,7 @@ export interface SecurityHeadersOptions {
 }
 
 const HSTS_VALUE = 'max-age=31536000';
+const CONTENT_SECURITY_POLICY = "default-src 'self'; img-src 'self' data: blob:";
 
 /**
  * Build the `onSend` hook. Returns the payload unchanged so Fastify continues
@@ -36,7 +38,7 @@ export function createSecurityHeadersHook(
   return async (_req, reply, payload) => {
     reply.header('X-Content-Type-Options', 'nosniff');
     reply.header('Referrer-Policy', 'no-referrer');
-    reply.header('Content-Security-Policy', "default-src 'self'");
+    reply.header('Content-Security-Policy', CONTENT_SECURITY_POLICY);
     if (opts.tls === true) {
       reply.header('Strict-Transport-Security', HSTS_VALUE);
     }
diff --git a/packages/kap-server/test/hostExposure.e2e.test.ts b/packages/kap-server/test/hostExposure.e2e.test.ts
index 7e62ebf7ea..da03e9a78a 100644
--- a/packages/kap-server/test/hostExposure.e2e.test.ts
+++ b/packages/kap-server/test/hostExposure.e2e.test.ts
@@ -115,7 +115,9 @@ describe('real password path (verifyPassword)', () => {
     });
     expect(res.status).toBe(200);
     expect(res.headers.get('x-content-type-options')).toBe('nosniff');
-    expect(res.headers.get('content-security-policy')).toBe("default-src 'self'");
+    expect(res.headers.get('content-security-policy')).toBe(
+      "default-src 'self'; img-src 'self' data: blob:",
+    );
   });
 
   it('accepts the persistent token on a public bind', async () => {
diff --git a/packages/kap-server/test/securityExposure.test.ts b/packages/kap-server/test/securityExposure.test.ts
index 169b6fd382..4d4fdc06c2 100644
--- a/packages/kap-server/test/securityExposure.test.ts
+++ b/packages/kap-server/test/securityExposure.test.ts
@@ -72,7 +72,9 @@ describe('server-v2 exposure hardening hooks', () => {
     expect(res.statusCode).toBe(200);
     expect(res.headers['x-content-type-options']).toBe('nosniff');
     expect(res.headers['referrer-policy']).toBe('no-referrer');
-    expect(res.headers['content-security-policy']).toBe("default-src 'self'");
+    expect(res.headers['content-security-policy']).toBe(
+      "default-src 'self'; img-src 'self' data: blob:",
+    );
     expect(res.headers['strict-transport-security']).toBeUndefined();
   });