diff --git a/backend/version.py b/backend/version.py
index 23aaf67..06d1d39 100644
--- a/backend/version.py
+++ b/backend/version.py
@@ -1,6 +1,6 @@
 # Shinkan Jinkendo Version Information
 
-APP_VERSION = "0.8.87"
+APP_VERSION = "0.8.88"
 BUILD_DATE = "2026-05-11"
 DB_SCHEMA_VERSION = "20260511052"
 
@@ -30,10 +30,19 @@ MODULE_VERSIONS = {
     "membership": "1.0.0",
     "catalogs": "1.5.0",  # Updated: Trainer Contexts API (Migration 012)
     "maturity_models": "1.4.0",  # matrix_stack_bundle: vollständiger Katalog+Modelle+Bindings Export/Import
-    "content_reports": "1.0.0",  # P-13: Content-Melde-Backend (DSA-konform, Inbox-Integration, P-11 Legal Hold)
+    "content_reports": "1.1.0",  # P-13: Melde-Button in Medienbibliothek + ExerciseAttachmentMediaStrip
 }
 
 CHANGELOG = [
+    {
+        "version": "0.8.88",
+        "date": "2026-05-11",
+        "changes": [
+            "Feat P-13: Melde-Button in Medienbibliothek (Grid + Liste) — öffnet ReportContentModal; nur aktive Medien ohne Legal Hold.",
+            "Feat P-13: Melde-Link an jedem Medium in ExerciseAttachmentMediaStrip (Lesemodus Übung).",
+            "Feat P-13: ReportContentModal — wiederverwendbares Formular (Grund, Beschreibung, Name, E-Mail, Gutglaubenserklärung); Vorausfüllung für eingeloggte Nutzer.",
+        ],
+    },
     {
         "version": "0.8.87",
         "date": "2026-05-11",
diff --git a/frontend/src/components/ExerciseAttachmentMediaStrip.jsx b/frontend/src/components/ExerciseAttachmentMediaStrip.jsx
index 503868a..aa6d697 100644
--- a/frontend/src/components/ExerciseAttachmentMediaStrip.jsx
+++ b/frontend/src/components/ExerciseAttachmentMediaStrip.jsx
@@ -4,6 +4,7 @@
 import React, { useMemo, useState } from 'react'
 import ExerciseMediaEmbed from './ExerciseMediaEmbed'
 import ExerciseMediaThumbTile from './ExerciseMediaThumbTile'
+import ReportContentModal from './ReportContentModal'
 import { resolveExerciseMediaFileUrl } from '../utils/exerciseMediaUrl'
 import {
   collectInlineExerciseMediaIdsFromExercise,
@@ -15,6 +16,7 @@ function isTrashHidden(m) {
 
 export default function ExerciseAttachmentMediaStrip({ exerciseId, exercise }) {
   const [preview, setPreview] = useState(null)
+  const [reportTarget, setReportTarget] = useState(null)
   const inlineIds = useMemo(() => collectInlineExerciseMediaIdsFromExercise(exercise), [exercise])
 
   const orphans = useMemo(() => {
@@ -56,10 +58,37 @@ export default function ExerciseAttachmentMediaStrip({ exerciseId, exercise }) {
                 </div>
               </div>
               <ExerciseMediaEmbed exerciseId={exerciseId} media={m} layoutSize="medium" />
+              {(m.asset_lifecycle_state || 'active') === 'active' && !m.asset_legal_hold_active && (
+                <button
+                  type="button"
+                  onClick={() => setReportTarget(m)}
+                  style={{
+                    background: 'none',
+                    border: 'none',
+                    padding: '4px 0 0',
+                    cursor: 'pointer',
+                    fontSize: '0.72rem',
+                    color: 'var(--text3)',
+                    textDecoration: 'underline',
+                    textAlign: 'left',
+                  }}
+                >
+                  Inhalt melden
+                </button>
+              )}
             </article>
           )
         })}
       </div>
+      {reportTarget && (
+        <ReportContentModal
+          targetType="media_asset"
+          targetId={reportTarget.media_asset_id || reportTarget.id}
+          targetLabel={reportTarget.title || reportTarget.original_filename || `Medium #${reportTarget.id}`}
+          onClose={() => setReportTarget(null)}
+        />
+      )}
+
       {preview && (
         <div
           role="dialog"
diff --git a/frontend/src/components/ReportContentModal.jsx b/frontend/src/components/ReportContentModal.jsx
new file mode 100644
index 0000000..fb3ad57
--- /dev/null
+++ b/frontend/src/components/ReportContentModal.jsx
@@ -0,0 +1,195 @@
+/**
+ * Wiederverwendbares Melde-Modal (P-13).
+ * Props:
+ *   targetType  – 'media_asset' | 'exercise'
+ *   targetId    – ID des Zielobjekts
+ *   targetLabel – Anzeigename für den Header (z.B. Dateiname oder Übungstitel)
+ *   onClose     – Callback zum Schließen
+ */
+import React, { useState } from 'react'
+import { useAuth } from '../context/AuthContext'
+import api from '../utils/api'
+
+const REASON_OPTIONS = [
+  { value: '', label: '— Grund auswählen —' },
+  { value: 'copyright', label: 'Urheberrechtsverletzung' },
+  { value: 'image_rights', label: 'Bildrechtsverletzung / Recht am eigenen Bild' },
+  { value: 'privacy', label: 'Datenschutz / Persönlichkeitsrecht' },
+  { value: 'minors', label: 'Darstellung Minderjähriger' },
+  { value: 'illegal_content', label: 'Rechtswidriger Inhalt' },
+  { value: 'youth_protection', label: 'Jugendschutz' },
+  { value: 'offensive_content', label: 'Beleidigender / anstößiger Inhalt' },
+  { value: 'other', label: 'Sonstiges' },
+]
+
+export default function ReportContentModal({ targetType, targetId, targetLabel, onClose }) {
+  const { user } = useAuth()
+
+  const [reason, setReason] = useState('')
+  const [description, setDescription] = useState('')
+  const [name, setName] = useState(user?.name || '')
+  const [email, setEmail] = useState(user?.email || '')
+  const [confirmed, setConfirmed] = useState(false)
+  const [saving, setSaving] = useState(false)
+  const [error, setError] = useState(null)
+  const [success, setSuccess] = useState(false)
+
+  async function handleSubmit(e) {
+    e.preventDefault()
+    if (!reason) { setError('Bitte einen Meldegrund auswählen.'); return }
+    if (description.trim().length < 10) { setError('Beschreibung muss mindestens 10 Zeichen haben.'); return }
+    if (!name.trim()) { setError('Bitte deinen Namen eingeben.'); return }
+    if (!email.trim()) { setError('Bitte deine E-Mail-Adresse eingeben.'); return }
+    if (!confirmed) { setError('Bitte bestätige die Gutglaubenserklärung.'); return }
+
+    setSaving(true)
+    setError(null)
+    try {
+      await api.submitContentReport({
+        target_type: targetType,
+        target_id: targetId,
+        report_reason: reason,
+        report_description: description.trim(),
+        reporter_name: name.trim(),
+        reporter_email: email.trim(),
+        good_faith_confirmed: true,
+      })
+      setSuccess(true)
+    } catch (err) {
+      setError(err.message || String(err))
+    } finally {
+      setSaving(false)
+    }
+  }
+
+  return (
+    <div
+      style={{
+        position: 'fixed',
+        inset: 0,
+        background: 'rgba(0,0,0,0.55)',
+        display: 'flex',
+        alignItems: 'center',
+        justifyContent: 'center',
+        zIndex: 1200,
+        padding: '1rem',
+        overflowY: 'auto',
+      }}
+      onClick={(e) => { if (e.target === e.currentTarget) onClose() }}
+    >
+      <div
+        style={{
+          background: 'var(--surface)',
+          borderRadius: '12px',
+          padding: '1.5rem',
+          maxWidth: '480px',
+          width: '100%',
+          marginTop: '2rem',
+          marginBottom: '2rem',
+        }}
+      >
+        <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: '1rem' }}>
+          <h2 style={{ margin: 0, fontSize: '1.1rem' }}>Inhalt melden</h2>
+          <button type="button" className="btn btn-secondary" style={{ padding: '4px 10px' }} onClick={onClose}>✕</button>
+        </div>
+
+        {targetLabel && (
+          <p className="muted" style={{ fontSize: '0.85rem', marginBottom: '1rem', marginTop: 0 }}>
+            {targetType === 'media_asset' ? 'Medium' : 'Übung'}: <strong>{targetLabel}</strong>
+          </p>
+        )}
+
+        {success ? (
+          <div>
+            <p style={{ color: 'var(--accent)', fontWeight: 600 }}>Meldung eingegangen.</p>
+            <p className="muted" style={{ fontSize: '0.9rem' }}>
+              Deine Meldung wurde gespeichert und wird von unseren Moderatoren geprüft. Vielen Dank.
+            </p>
+            <button type="button" className="btn btn-primary btn-full" onClick={onClose}>
+              Schließen
+            </button>
+          </div>
+        ) : (
+          <form onSubmit={handleSubmit}>
+            <div className="form-row">
+              <label className="form-label">Meldegrund *</label>
+              <select
+                className="form-input"
+                value={reason}
+                onChange={(e) => setReason(e.target.value)}
+                required
+              >
+                {REASON_OPTIONS.map((o) => (
+                  <option key={o.value} value={o.value}>{o.label}</option>
+                ))}
+              </select>
+            </div>
+
+            <div className="form-row">
+              <label className="form-label">Beschreibung * (mind. 10 Zeichen)</label>
+              <textarea
+                className="form-input"
+                rows={3}
+                value={description}
+                onChange={(e) => setDescription(e.target.value)}
+                placeholder="Bitte erläutere kurz, warum du diesen Inhalt meldest."
+                required
+              />
+            </div>
+
+            <div className="form-row">
+              <label className="form-label">Dein Name *</label>
+              <input
+                type="text"
+                className="form-input"
+                value={name}
+                onChange={(e) => setName(e.target.value)}
+                required
+              />
+            </div>
+
+            <div className="form-row">
+              <label className="form-label">Deine E-Mail-Adresse *</label>
+              <input
+                type="email"
+                className="form-input"
+                value={email}
+                onChange={(e) => setEmail(e.target.value)}
+                required
+              />
+            </div>
+
+            <div className="form-row">
+              <label style={{ display: 'flex', gap: '0.6rem', alignItems: 'flex-start', cursor: 'pointer' }}>
+                <input
+                  type="checkbox"
+                  checked={confirmed}
+                  onChange={(e) => setConfirmed(e.target.checked)}
+                  style={{ marginTop: '3px', flexShrink: 0 }}
+                />
+                <span style={{ fontSize: '0.85rem', color: 'var(--text2)' }}>
+                  Ich melde diesen Inhalt nach bestem Wissen und Gewissen. Ich bestätige, dass meine Meldung
+                  nicht missbräuchlich ist und ich der Überzeugung bin, dass der gemeldete Inhalt rechtswidrig
+                  ist oder gegen die Nutzungsbedingungen verstößt.
+                </span>
+              </label>
+            </div>
+
+            {error && (
+              <p style={{ color: 'var(--danger)', fontSize: '0.88rem', margin: '0.5rem 0' }}>{error}</p>
+            )}
+
+            <div style={{ display: 'flex', gap: '0.5rem', marginTop: '1rem' }}>
+              <button type="submit" className="btn btn-primary" style={{ flex: 1 }} disabled={saving}>
+                {saving ? 'Wird gesendet…' : 'Meldung absenden'}
+              </button>
+              <button type="button" className="btn btn-secondary" onClick={onClose} disabled={saving}>
+                Abbrechen
+              </button>
+            </div>
+          </form>
+        )}
+      </div>
+    </div>
+  )
+}
diff --git a/frontend/src/pages/MediaLibraryPage.jsx b/frontend/src/pages/MediaLibraryPage.jsx
index 3244781..885581e 100644
--- a/frontend/src/pages/MediaLibraryPage.jsx
+++ b/frontend/src/pages/MediaLibraryPage.jsx
@@ -25,6 +25,7 @@ import api from '../utils/api'
 import { activeClubMemberships } from '../utils/activeClub'
 import { resolveMediaAssetFileUrl } from '../utils/exerciseMediaUrl'
 import RightsDeclarationDialog from '../components/RightsDeclarationDialog'
+import ReportContentModal from '../components/ReportContentModal'
 
 const LC_OPTIONS = [
   { value: 'active', label: 'Aktiv' },
@@ -317,6 +318,7 @@ export default function MediaLibraryPage() {
   const [bulkApplyVis, setBulkApplyVis] = useState(false)
   const [busy, setBusy] = useState(false)
   const [preview, setPreview] = useState(null)
+  const [reportTarget, setReportTarget] = useState(null)
   const [mediaKind, setMediaKind] = useState('all')
   const [filterClubId, setFilterClubId] = useState('')
   const [filterUploaderId, setFilterUploaderId] = useState('')
@@ -986,6 +988,24 @@ export default function MediaLibraryPage() {
                       </div>
                     ) : null}
                     <MediaUsageBlock usage={it.usage} compact />
+                    {(it.lifecycle_state || 'active') === 'active' && !it.legal_hold_active && (
+                      <button
+                        type="button"
+                        onClick={() => setReportTarget(it)}
+                        style={{
+                          background: 'none',
+                          border: 'none',
+                          padding: '2px 0 0',
+                          cursor: 'pointer',
+                          fontSize: '0.72rem',
+                          color: 'var(--text3)',
+                          textDecoration: 'underline',
+                          textAlign: 'left',
+                        }}
+                      >
+                        Melden
+                      </button>
+                    )}
                   </div>
                 </div>
               )
@@ -1045,7 +1065,7 @@ export default function MediaLibraryPage() {
                       {viewer?.show_uploader_meta ? (
                         <td className="media-library__td-sub">{uploaderLabel(it, viewer) || '—'}</td>
                       ) : null}
-                      <td>
+                      <td style={{ whiteSpace: 'nowrap' }}>
                         <button
                           type="button"
                           className="media-library__icon-btn"
@@ -1054,6 +1074,18 @@ export default function MediaLibraryPage() {
                         >
                           <MoreVertical size={18} />
                         </button>
+                        {(it.lifecycle_state || 'active') === 'active' && !it.legal_hold_active && (
+                          <button
+                            type="button"
+                            className="media-library__icon-btn"
+                            onClick={() => setReportTarget(it)}
+                            aria-label="Melden"
+                            title="Inhalt melden"
+                            style={{ color: 'var(--text3)', fontSize: '0.72rem', padding: '4px 6px' }}
+                          >
+                            Melden
+                          </button>
+                        )}
                       </td>
                     </tr>
                   )
@@ -2026,6 +2058,15 @@ export default function MediaLibraryPage() {
           </div>
         </div>
       ) : null}
+
+      {reportTarget && (
+        <ReportContentModal
+          targetType="media_asset"
+          targetId={reportTarget.id}
+          targetLabel={reportTarget.original_filename || `Medium #${reportTarget.id}`}
+          onClose={() => setReportTarget(null)}
+        />
+      )}
     </div>
   )
 }
diff --git a/frontend/src/version.js b/frontend/src/version.js
index 5aa6e1e..8efb9c6 100644
--- a/frontend/src/version.js
+++ b/frontend/src/version.js
@@ -1,6 +1,6 @@
 // Shinkan Jinkendo Frontend Version
 
-export const APP_VERSION = "0.8.87"
+export const APP_VERSION = "0.8.88"
 export const BUILD_DATE = "2026-05-11"
 
 export const PAGE_VERSIONS = {
@@ -26,4 +26,6 @@ export const PAGE_VERSIONS = {
   ExerciseMediaEmbed: "1.1.0",  // P-11: Legal-Hold-Placeholder statt Datei
   ExerciseMediaThumbTile: "1.1.0",  // P-11: Legal-Hold-Kachel statt Datei-Vorschau
   InboxPage: "2.0.0",  // P-13: Inhaltsmeldungen-Abschnitt integriert
+  MediaLibraryPage: "1.7.0",  // P-13: Melde-Button an Medienkacheln
+  ExerciseAttachmentMediaStrip: "1.1.0",  // P-13: Melde-Link an angehängten Medien
 }