diff --git a/api/changelog.d/selfhosted-published-signing-key.security.md b/api/changelog.d/selfhosted-published-signing-key.security.md
new file mode 100644
index 0000000000..623c6f7871
--- /dev/null
+++ b/api/changelog.d/selfhosted-published-signing-key.security.md
@@ -0,0 +1 @@
+API refuses to start with a JWT signing key published in this repository, and the Helm minimal-installation example no longer ships working secrets
diff --git a/api/src/backend/api/apps.py b/api/src/backend/api/apps.py
index 40cf71866e..87d1d2148b 100644
--- a/api/src/backend/api/apps.py
+++ b/api/src/backend/api/apps.py
@@ -38,6 +38,15 @@ PUBLISHED_ENCRYPTION_KEY_DIGESTS = frozenset(
     }
 )
 
+# SHA-256 of the base64 body of JWT signing keys that were committed to this
+# repository with a working value. Anyone holding one can forge tokens.
+PUBLISHED_SIGNING_KEY_DIGESTS = frozenset(
+    {
+        # contrib/k8s/helm/prowler-app/examples/minimal-installation/secrets.yaml
+        "375d5755ab4a7d38c58b38c67c1a6d1cab5afc91844445d8489c15ce7779d949",
+    }
+)
+
 ENCRYPTION_KEY_DOCS = (
     "https://docs.prowler.com/getting-started/installation/prowler-app"
     "#secrets-encryption-key"
@@ -50,6 +59,16 @@ def _digest(value):
     return hashlib.sha256(value.encode()).hexdigest()
 
 
+def _pem_digest(value):
+    """Digest of a PEM's base64 body, so indentation and line wrapping do not matter."""
+    body = "".join(
+        line.strip()
+        for line in value.splitlines()
+        if line.strip() and "-----" not in line
+    )
+    return _digest(body)
+
+
 class ApiConfig(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
     name = "api"
@@ -207,6 +226,16 @@ class ApiConfig(AppConfig):
         signing_key = env.str(SIGNING_KEY_ENV, default="").strip()
         verifying_key = env.str(VERIFYING_KEY_ENV, default="").strip()
 
+        if signing_key and _pem_digest(signing_key) in PUBLISHED_SIGNING_KEY_DIGESTS:
+            raise ImproperlyConfigured(
+                f"'{SIGNING_KEY_ENV}' is set to a key pair that was published in the "
+                "Prowler repository and is therefore public. Anyone holding it can "
+                "forge API tokens. Generate a new pair with 'openssl genrsa -out "
+                "private.pem 2048' and 'openssl rsa -in private.pem -pubout', set both "
+                "variables and restart. Existing sessions end and users sign in again; "
+                "no stored data needs re-encrypting."
+            )
+
         if not signing_key or not verifying_key:
             logger.info(
                 f"Generating JWT RSA key pair. In production, set '{SIGNING_KEY_ENV}' and '{VERIFYING_KEY_ENV}' "
diff --git a/api/src/backend/api/tests/test_apps.py b/api/src/backend/api/tests/test_apps.py
index 667ce52cef..fe61873fe4 100644
--- a/api/src/backend/api/tests/test_apps.py
+++ b/api/src/backend/api/tests/test_apps.py
@@ -251,6 +251,40 @@ def test_ensure_secrets_refuses_published_encryption_key(monkeypatch, secrets_di
     assert not (secrets_dir / ENCRYPTION_KEY_FILE).exists()
 
 
+def test_ensure_crypto_keys_refuses_published_signing_key(monkeypatch, tmp_path):
+    published, verifying = _stub_keys()
+    monkeypatch.setattr(
+        api_apps_module, "KEYS_DIRECTORY", Path(tmp_path), raising=False
+    )
+    monkeypatch.setattr(api_apps_module, "_keys_initialized", False, raising=False)
+    monkeypatch.setenv(SIGNING_KEY_ENV, published)
+    monkeypatch.setenv(VERIFYING_KEY_ENV, verifying)
+    monkeypatch.setattr(settings, "TESTING", False, raising=False)
+    monkeypatch.setattr(
+        api_apps_module,
+        "PUBLISHED_SIGNING_KEY_DIGESTS",
+        frozenset({api_apps_module._pem_digest(published)}),
+        raising=False,
+    )
+
+    with pytest.raises(ImproperlyConfigured) as exc_info:
+        ApiConfig("api", api_apps_module)._ensure_crypto_keys()
+
+    assert SIGNING_KEY_ENV in str(exc_info.value)
+    assert "PRIVATE" not in str(exc_info.value)
+    assert not (Path(tmp_path) / PRIVATE_KEY_FILE).exists()
+
+
+def test_pem_digest_ignores_indentation_and_wrapping():
+    # derived from the existing stub so no PEM literal is added to this file
+    flat = _stub_keys()[0]
+    indented = "".join(f"    {line}\n" for line in flat.splitlines())
+    wrapped = flat.replace("PRIVATE\n", "PRIV\nATE\n", 1)
+
+    assert api_apps_module._pem_digest(indented) == api_apps_module._pem_digest(flat)
+    assert api_apps_module._pem_digest(wrapped) == api_apps_module._pem_digest(flat)
+
+
 def test_ensure_secrets_generates_encryption_key_when_empty(secrets_dir):
     _make_app()._ensure_secrets()
 
diff --git a/contrib/k8s/helm/prowler-app/README.md b/contrib/k8s/helm/prowler-app/README.md
index 544b5f39a7..835c26137c 100644
--- a/contrib/k8s/helm/prowler-app/README.md
+++ b/contrib/k8s/helm/prowler-app/README.md
@@ -86,7 +86,7 @@ Before installing the Helm chart, you must create a Kubernetes Secret containing
      NEO4J_AUTH: "neo4j/[prowler-password]"
    ```
 
-   > **Note:** You can use the [example secrets file](./examples/minimal-installation/secrets.yaml) as a template, but **always replace the placeholder values with your own secure keys** before applying.
+   > **Note:** You can use the [example secrets file](./examples/minimal-installation/secrets.yaml) as a template, but **always replace the placeholder values with your own secure keys** before applying. Earlier revisions of that example shipped working values; the API refuses to start with any key that was published in this repository, so a deployment still using one must generate a new one.
 
 3. **Apply the secret to your cluster:**
 
diff --git a/contrib/k8s/helm/prowler-app/examples/minimal-installation/secrets.yaml b/contrib/k8s/helm/prowler-app/examples/minimal-installation/secrets.yaml
index 2e379ef5c8..254cf85d69 100644
--- a/contrib/k8s/helm/prowler-app/examples/minimal-installation/secrets.yaml
+++ b/contrib/k8s/helm/prowler-app/examples/minimal-installation/secrets.yaml
@@ -4,54 +4,28 @@ type: Opaque
 metadata:
   name: prowler-secret
 stringData:
+  # Every value below must be generated for your own installation. The values that
+  # used to ship here were public, and the API refuses to start with them.
+
   # openssl genrsa -out private.pem 2048
   DJANGO_TOKEN_SIGNING_KEY: |
     -----BEGIN PRIVATE KEY-----
-    MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCIro0QiLAxw7rF
-    GO0NgAWJfkpYE5ysMGDCbId07HUrv+/SCoRjqKVzGJVIvmNP5oByzSehPgswW9v3
-    3dqe2r9sCS1JyMa+XO3qfZCR0uRDcPCwZjIyr0QQLpWAymdBa8baeHsU1/3Orjcb
-    Vrr+lNx4HQJOiSn094iXPReW/25hYeq/SXs79V2CR87PGdoZAhb8IllAxJgdfkeB
-    /iWohY/1vfRTmIuMweWGXk0aKzPsBdvE/DqG4HjiNVEPh18G3vid0YTZNmm7u8vO
-    Cue3x9NQWGHA4QtxNtLtxlHcOEryqZ9ChO2nC+ew0Xl/v706XFNyLFicjisIKNQo
-    qdkaMS33AgMBAAECggEAGdJIChCYoL4mYafk2MEPyrrWFq+V0J3PGcvhB0DInfxD
-    tT2RZzZsE0NYqIZ3Qpf8OjPxwa9z863W74u1Cn+u3B0bti29BieONteD4VijEO6c
-    OecEorijth7m1Y7nVN+kkI9kSTrI0yvsczi+WOwMfpCUZ/vXtlSxNEkxVLBqzPCo
-    9VxAFIjgWOj2rpw8nxPedves36PUrC5ghLqrOTe1jmw/Di0++47AXG+DsTXc00sc
-    5+oybopm3Kimsxrqbf9s8SZf2A8NiwqcbLj8OtP2j2g4TCEgZYLD5Zmt+JN/wN4B
-    WsQG/Hwp4KPPm9QTHEpuuoPFP1CZWZeq8gPcV4apYQKBgQC+TuXjJCYhZqNIttTZ
-    z/i3hkKUEKQLkzTZnXaDzL5wHyEMVqM2E/WkilO0C9ZZwh0ENPzkp+JsHf7LEhHy
-    wSHOti81VzUCjN/YpCBKlOlClqSiDlOonImrobLei8xgvmA0VmGtirCXZyyzZUoV
-    OyPr17WpK6G/M5piX59MvKQg0QKBgQC33NBoQFD8A6FjrTopYmWfK099k9uQh9NE
-    bvUYsNAPunSDslmc/0PPHQC7fRX5Ime2BinXAN1PYtB/Fsu3jv/+FCUM5hVil0Dd
-    KBvt13+RYSCJKlhcGP1EkWoIg1F2XXBOZKJrC8VQ+Vyl2t06UcWQqy5M9J4VZaqI
-    fruOLU/URwKBgE55GjJfZZnASPRi78IhD94dbra/ZeWf/dr+IzCV7LEvJOGBmCtk
-    b5Y5s+o6N1krwetKLj3bPHJ4q+fwu5XuLZKfbTgBjcpPbL5YbzhRzx22IIzye2y7
-    n8k2FBvQaaY62lC6jeyRk9/am4Qd8D5w9I77k9z+MOQ20yJda8KoxsUBAoGBAIQ9
-    5QPmppjsf4ry0C9t30uhWhYnX7fPiYviBpVQrwVxBVan076Q9xOjd6BicohzT4bj
-    XfqPW546o12VZsbKqqLzmEZzwpPb2EJ5E8V4xv8ojb86Xr03GArWUB55XQE2aY1o
-    4kz99VitUg7UoWPN5ryL8sxU8NLRAdwU0w+K1a0HAoGAZaU7O94u9IIPZ6Ohobs2
-    Vjf/eV0brCKgX61b4z/YhuJdZsyTujhBZUihZwqR696kiFKuzmHx1ghE2ITvnPVN
-    q0iHxRZzBCnRQ+mQlS0trzphaCP0NVy3osFeAD9mJfnOnSmkU0ua4F81mkvke1eN
-    6nnaoAdy2lmMr96/Tye2ty4=
+    REPLACE WITH THE CONTENTS OF private.pem
     -----END PRIVATE KEY-----
 
   # openssl rsa -in private.pem -pubout -out public.pem
   DJANGO_TOKEN_VERIFYING_KEY: |
     -----BEGIN PUBLIC KEY-----
-    MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAiK6NEIiwMcO6xRjtDYAF
-    iX5KWBOcrDBgwmyHdOx1K7/v0gqEY6ilcxiVSL5jT+aAcs0noT4LMFvb993antq/
-    bAktScjGvlzt6n2QkdLkQ3DwsGYyMq9EEC6VgMpnQWvG2nh7FNf9zq43G1a6/pTc
-    eB0CTokp9PeIlz0Xlv9uYWHqv0l7O/VdgkfOzxnaGQIW/CJZQMSYHX5Hgf4lqIWP
-    9b30U5iLjMHlhl5NGisz7AXbxPw6huB44jVRD4dfBt74ndGE2TZpu7vLzgrnt8fT
-    UFhhwOELcTbS7cZR3DhK8qmfQoTtpwvnsNF5f7+9OlxTcixYnI4rCCjUKKnZGjEt
-    9wIDAQAB
+    REPLACE WITH THE CONTENTS OF public.pem
     -----END PUBLIC KEY-----
 
   # openssl rand -base64 32
-  DJANGO_SECRETS_ENCRYPTION_KEY: "qYAIWnRK52aBT5YQkBoMEw08j7j3+QIPZXS6+A8Su44="
+  # Protects stored provider, integration and LLM credentials. Changing it later
+  # leaves the existing ones unreadable, so set it before the first scan.
+  DJANGO_SECRETS_ENCRYPTION_KEY: ""
 
   # openssl rand -base64 32
-  AUTH_SECRET: "CM9w3Nco2P1RdHaYmD+fmy2nJmSofusdHd4g7Z4KDG4="
+  AUTH_SECRET: ""
 
   # Unfortunatelly, we need to duplicate the password in two different keys because the Neo4j Helm Chart expects the password in the NEO4J_AUTH key and the application expects it in the NEO4J_PASSWORD key.
   NEO4J_PASSWORD: "prowler-password-fake"