From a5d4b2d4c9e46bfa11c82f85fdc2bcc0b50ae681 Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Wed, 25 Feb 2026 23:48:19 +0800
Subject: [PATCH 01/12] fix(jose): do not use header's jwk automatically

---
 authlib/jose/rfc7515/jws.py | 2 --
 authlib/jose/rfc7516/jwe.py | 2 --
 2 files changed, 4 deletions(-)

diff --git a/authlib/jose/rfc7515/jws.py b/authlib/jose/rfc7515/jws.py
index 65a7e973..d9f5cae4 100644
--- a/authlib/jose/rfc7515/jws.py
+++ b/authlib/jose/rfc7515/jws.py
@@ -269,8 +269,6 @@ def _prepare_algorithm_key(self, header, payload, key):
         algorithm = self.ALGORITHMS_REGISTRY[alg]
         if callable(key):
             key = key(header, payload)
-        elif key is None and "jwk" in header:
-            key = header["jwk"]
         key = algorithm.prepare_key(key)
         return algorithm, key
 
diff --git a/authlib/jose/rfc7516/jwe.py b/authlib/jose/rfc7516/jwe.py
index e58a7b7c..6393ad5f 100644
--- a/authlib/jose/rfc7516/jwe.py
+++ b/authlib/jose/rfc7516/jwe.py
@@ -754,6 +754,4 @@ def _validate_private_headers(self, header, alg):
 def prepare_key(alg, header, key):
     if callable(key):
         key = key(header, None)
-    elif key is None and "jwk" in header:
-        key = header["jwk"]
     return alg.prepare_key(key)

From 48b345f29f6c459f11c6a40162b6c0b742ef2e22 Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Thu, 26 Feb 2026 00:10:46 +0800
Subject: [PATCH 02/12] fix(jose): remove deprecated algorithm from default
 registry

---
 authlib/jose/rfc7515/jws.py      |  8 ++++++--
 authlib/jose/rfc7515/models.py   |  1 +
 authlib/jose/rfc7516/jwe.py      | 14 +++++++++++---
 authlib/jose/rfc7516/models.py   |  1 +
 authlib/jose/rfc7518/jwe_algs.py |  1 +
 authlib/jose/rfc7518/jws_algs.py |  1 +
 6 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/authlib/jose/rfc7515/jws.py b/authlib/jose/rfc7515/jws.py
index d9f5cae4..92e24ce5 100644
--- a/authlib/jose/rfc7515/jws.py
+++ b/authlib/jose/rfc7515/jws.py
@@ -261,12 +261,16 @@ def _prepare_algorithm_key(self, header, payload, key):
             raise MissingAlgorithmError()
 
         alg = header["alg"]
-        if self._algorithms is not None and alg not in self._algorithms:
-            raise UnsupportedAlgorithmError()
         if alg not in self.ALGORITHMS_REGISTRY:
             raise UnsupportedAlgorithmError()
 
         algorithm = self.ALGORITHMS_REGISTRY[alg]
+        if self._algorithms is None:
+            if algorithm.deprecated:
+                raise UnsupportedAlgorithmError()
+        elif alg not in self._algorithms:
+            raise UnsupportedAlgorithmError()
+
         if callable(key):
             key = key(header, payload)
         key = algorithm.prepare_key(key)
diff --git a/authlib/jose/rfc7515/models.py b/authlib/jose/rfc7515/models.py
index d14fb641..b1261b42 100644
--- a/authlib/jose/rfc7515/models.py
+++ b/authlib/jose/rfc7515/models.py
@@ -5,6 +5,7 @@ class JWSAlgorithm:
 
     name = None
     description = None
+    deprecated = False
     algorithm_type = "JWS"
     algorithm_location = "alg"
 
diff --git a/authlib/jose/rfc7516/jwe.py b/authlib/jose/rfc7516/jwe.py
index 6393ad5f..3cfc9372 100644
--- a/authlib/jose/rfc7516/jwe.py
+++ b/authlib/jose/rfc7516/jwe.py
@@ -697,11 +697,19 @@ def get_header_alg(self, header):
             raise MissingAlgorithmError()
 
         alg = header["alg"]
-        if self._algorithms is not None and alg not in self._algorithms:
-            raise UnsupportedAlgorithmError()
         if alg not in self.ALG_REGISTRY:
             raise UnsupportedAlgorithmError()
-        return self.ALG_REGISTRY[alg]
+
+        instance = self.ALG_REGISTRY[alg]
+
+        # use all ALG_REGISTRY algorithms
+        if self._algorithms is None:
+            # do not use deprecated algorithms
+            if instance.deprecated:
+                raise UnsupportedAlgorithmError()
+        elif alg not in self._algorithms:
+            raise UnsupportedAlgorithmError()
+        return instance
 
     def get_header_enc(self, header):
         if "enc" not in header:
diff --git a/authlib/jose/rfc7516/models.py b/authlib/jose/rfc7516/models.py
index 2bcca8c8..ce98257f 100644
--- a/authlib/jose/rfc7516/models.py
+++ b/authlib/jose/rfc7516/models.py
@@ -9,6 +9,7 @@ class JWEAlgorithmBase(metaclass=ABCMeta):  # noqa: B024
 
     name = None
     description = None
+    deprecated = False
     algorithm_type = "JWE"
     algorithm_location = "alg"
 
diff --git a/authlib/jose/rfc7518/jwe_algs.py b/authlib/jose/rfc7518/jwe_algs.py
index e22718a0..2c73a654 100644
--- a/authlib/jose/rfc7518/jwe_algs.py
+++ b/authlib/jose/rfc7518/jwe_algs.py
@@ -52,6 +52,7 @@ class RSAAlgorithm(JWEAlgorithm):
 
     def __init__(self, name, description, pad_fn):
         self.name = name
+        self.deprecated = name == "RSA1_5"
         self.description = description
         self.padding = pad_fn
 
diff --git a/authlib/jose/rfc7518/jws_algs.py b/authlib/jose/rfc7518/jws_algs.py
index 3f97530a..c9e95ec5 100644
--- a/authlib/jose/rfc7518/jws_algs.py
+++ b/authlib/jose/rfc7518/jws_algs.py
@@ -27,6 +27,7 @@
 class NoneAlgorithm(JWSAlgorithm):
     name = "none"
     description = "No digital signature or MAC performed"
+    deprecated = True
 
     def prepare_key(self, raw_data):
         return None

From 5be3c518794b7322375bae2bf1871713d9b5c2fb Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Thu, 26 Feb 2026 00:11:18 +0800
Subject: [PATCH 03/12] fix(jose): add ES256K into default jwt algorithms

---
 authlib/jose/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/authlib/jose/__init__.py b/authlib/jose/__init__.py
index 165ef9a1..6670549f 100644
--- a/authlib/jose/__init__.py
+++ b/authlib/jose/__init__.py
@@ -55,6 +55,7 @@
         "RS384",
         "RS512",
         "ES256",
+        "ES256K",
         "ES384",
         "ES512",
         "PS256",

From 1b0a1d988842bff7347c4ec0a70e45c3ba55504e Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Thu, 26 Feb 2026 00:21:16 +0800
Subject: [PATCH 04/12] fix(jose): generate random cek when cek length doesn't
 match

---
 authlib/jose/rfc7518/jwe_algs.py | 13 ++++++-------
 tests/jose/test_chacha20.py      |  3 ++-
 tests/jose/test_jwe.py           |  2 +-
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/authlib/jose/rfc7518/jwe_algs.py b/authlib/jose/rfc7518/jwe_algs.py
index 2c73a654..778cc478 100644
--- a/authlib/jose/rfc7518/jwe_algs.py
+++ b/authlib/jose/rfc7518/jwe_algs.py
@@ -1,4 +1,4 @@
-import os
+import secrets
 import struct
 
 from cryptography.hazmat.backends import default_backend
@@ -41,7 +41,7 @@ def wrap(self, enc_alg, headers, key, preset=None):
     def unwrap(self, enc_alg, ek, headers, key):
         cek = key.get_op_key("decrypt")
         if len(cek) * 8 != enc_alg.CEK_SIZE:
-            raise ValueError('Invalid "cek" length')
+            cek = secrets.token_bytes(enc_alg.CEK_SIZE // 8)
         return cek
 
 
@@ -76,11 +76,10 @@ def wrap(self, enc_alg, headers, key, preset=None):
         return {"ek": ek, "cek": cek}
 
     def unwrap(self, enc_alg, ek, headers, key):
-        # it will raise ValueError if failed
         op_key = key.get_op_key("unwrapKey")
         cek = op_key.decrypt(ek, self.padding)
         if len(cek) * 8 != enc_alg.CEK_SIZE:
-            raise ValueError('Invalid "cek" length')
+            cek = secrets.token_bytes(enc_alg.CEK_SIZE // 8)
         return cek
 
 
@@ -119,7 +118,7 @@ def unwrap(self, enc_alg, ek, headers, key):
         self._check_key(op_key)
         cek = aes_key_unwrap(op_key, ek, default_backend())
         if len(cek) * 8 != enc_alg.CEK_SIZE:
-            raise ValueError('Invalid "cek" length')
+            cek = secrets.token_bytes(enc_alg.CEK_SIZE // 8)
         return cek
 
 
@@ -155,7 +154,7 @@ def wrap(self, enc_alg, headers, key, preset=None):
         #: The "iv" (initialization vector) Header Parameter value is the
         #: base64url-encoded representation of the 96-bit IV value
         iv_size = 96
-        iv = os.urandom(iv_size // 8)
+        iv = secrets.token_bytes(iv_size // 8)
 
         cipher = Cipher(AES(op_key), GCM(iv), backend=default_backend())
         enc = cipher.encryptor()
@@ -186,7 +185,7 @@ def unwrap(self, enc_alg, ek, headers, key):
         d = cipher.decryptor()
         cek = d.update(ek) + d.finalize()
         if len(cek) * 8 != enc_alg.CEK_SIZE:
-            raise ValueError('Invalid "cek" length')
+            cek = secrets.token_bytes(enc_alg.CEK_SIZE // 8)
         return cek
 
 
diff --git a/tests/jose/test_chacha20.py b/tests/jose/test_chacha20.py
index 5f39f359..aea4f110 100644
--- a/tests/jose/test_chacha20.py
+++ b/tests/jose/test_chacha20.py
@@ -1,4 +1,5 @@
 import pytest
+from cryptography.exceptions import InvalidTag
 
 from authlib.jose import JsonWebEncryption
 from authlib.jose import OctKey
@@ -16,7 +17,7 @@ def test_dir_alg_c20p():
     assert rv["payload"] == b"hello"
 
     key2 = OctKey.generate_key(128, is_private=True)
-    with pytest.raises(ValueError):
+    with pytest.raises(InvalidTag):
         jwe.deserialize_compact(data, key2)
 
     with pytest.raises(ValueError):
diff --git a/tests/jose/test_jwe.py b/tests/jose/test_jwe.py
index 2f476ca3..a59c9ad2 100644
--- a/tests/jose/test_jwe.py
+++ b/tests/jose/test_jwe.py
@@ -1143,7 +1143,7 @@ def test_dir_alg():
     assert rv["payload"] == b"hello"
 
     key2 = OctKey.generate_key(256, is_private=True)
-    with pytest.raises(ValueError):
+    with pytest.raises(InvalidTag):
         jwe.deserialize_compact(data, key2)
 
     with pytest.raises(ValueError):

From b9bb2b25bf8b7e01512d847a95c1749646eaa72b Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Sun, 1 Mar 2026 00:30:33 +0900
Subject: [PATCH 05/12] fix(oidc): fail close at validating c_hash and at_hash

---
 authlib/oidc/core/claims.py       |  4 ++--
 tests/core/test_oidc/test_core.py | 10 ++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/authlib/oidc/core/claims.py b/authlib/oidc/core/claims.py
index dc707730..9b1186b3 100644
--- a/authlib/oidc/core/claims.py
+++ b/authlib/oidc/core/claims.py
@@ -303,6 +303,6 @@ def get_claim_cls_by_response_type(response_type):
 
 def _verify_hash(signature, s, alg):
     hash_value = create_half_hash(s, alg)
-    if not hash_value:
-        return True
+    if hash_value is None:
+        return False
     return hmac.compare_digest(hash_value, to_bytes(signature))
diff --git a/tests/core/test_oidc/test_core.py b/tests/core/test_oidc/test_core.py
index 30fca3c5..0c0d6f01 100644
--- a/tests/core/test_oidc/test_core.py
+++ b/tests/core/test_oidc/test_core.py
@@ -99,9 +99,10 @@ def test_validate_at_hash():
     )
     claims.params = {"access_token": "a"}
 
-    # invalid alg won't raise
+    # invalid alg will raise too
     claims.header = {"alg": "HS222"}
-    claims.validate(1000)
+    with pytest.raises(InvalidClaimError):
+        claims.validate(1000)
 
     claims.header = {"alg": "HS256"}
     with pytest.raises(InvalidClaimError):
@@ -143,10 +144,11 @@ def test_hybrid_id_token():
     with pytest.raises(MissingClaimError):
         claims.validate(1000)
 
-    # invalid alg won't raise
+    # invalid alg will raise too
     claims.header = {"alg": "HS222"}
     claims["c_hash"] = "a"
-    claims.validate(1000)
+    with pytest.raises(InvalidClaimError):
+        claims.validate(1000)
 
     claims.header = {"alg": "HS256"}
     with pytest.raises(InvalidClaimError):

From 9266eaa2227ad7e21dc731b2a4a01909aabd934b Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Mon, 2 Mar 2026 16:42:53 +0900
Subject: [PATCH 06/12] chore: release 1.6.9

---
 authlib/consts.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/authlib/consts.py b/authlib/consts.py
index 69437da4..ed67bccf 100644
--- a/authlib/consts.py
+++ b/authlib/consts.py
@@ -1,5 +1,5 @@
 name = "Authlib"
-version = "1.6.8"
+version = "1.6.9"
 author = "Hsiaoming Yang <me@lepture.com>"
 homepage = "https://authlib.org"
 default_user_agent = f"{name}/{version} (+{homepage})"

From 3be08468201a7766a93012ce149ea12822cab096 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89loi=20Rivard?= <eloi@yaal.coop>
Date: Sun, 29 Mar 2026 09:21:42 +0200
Subject: [PATCH 07/12] fix: redirecting to unvalidated redirect_uri on
 UnsupportedResponseTypeError

---
 .../oauth2/rfc6749/authorization_server.py    | 13 +++++-
 docs/changelog.rst                            | 31 +++++++++++++
 .../test_authorization_code_grant.py          | 44 +++++++++++++++++++
 3 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/authlib/oauth2/rfc6749/authorization_server.py b/authlib/oauth2/rfc6749/authorization_server.py
index 928251dc..c484aa6c 100644
--- a/authlib/oauth2/rfc6749/authorization_server.py
+++ b/authlib/oauth2/rfc6749/authorization_server.py
@@ -241,10 +241,21 @@ def get_authorization_grant(self, request):
             if grant_cls.check_authorization_endpoint(request):
                 return _create_grant(grant_cls, extensions, request, self)
 
+        # Per RFC 6749 §4.1.2.1, only redirect with the error if the client
+        # exists and the redirect_uri has been validated against it.
+        redirect_uri = None
+        if client_id := request.payload.client_id:
+            if client := self.query_client(client_id):
+                if requested_uri := request.payload.redirect_uri:
+                    if client.check_redirect_uri(requested_uri):
+                        redirect_uri = requested_uri
+                else:
+                    redirect_uri = client.get_default_redirect_uri()
+
         raise UnsupportedResponseTypeError(
             f"The response type '{request.payload.response_type}' is not supported by the server.",
             request.payload.response_type,
-            redirect_uri=request.payload.redirect_uri,
+            redirect_uri=redirect_uri,
         )
 
     def get_consent_grant(self, request=None, end_user=None):
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 1e557f58..c35a911b 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -6,6 +6,37 @@ Changelog
 
 Here you can see the full list of changes between each Authlib release.
 
+Version 1.6.10
+--------------
+
+**Unreleased**
+
+- Fix redirecting to unvalidated ``redirect_uri`` on ``UnsupportedResponseTypeError``.
+
+Version 1.6.9
+-------------
+
+**Released on Mar 2, 2026**
+
+- Not using header's ``jwk`` automatically.
+- Add ``ES256K`` into default jwt algorithms.
+- Remove deprecated algorithm from default registry.
+- Generate random ``cek`` when ``cek`` length doesn't match.
+
+Version 1.6.8
+-------------
+
+**Released on Feb 17, 2026**
+
+- Add ``EdDSA`` to default ``jwt`` instance.
+
+Version 1.6.7
+-------------
+
+**Released on Feb 6, 2026**
+
+- Set supported algorithms for the default ``jwt`` instance.
+
 Version 1.6.6
 -------------
 
diff --git a/tests/flask/test_oauth2/test_authorization_code_grant.py b/tests/flask/test_oauth2/test_authorization_code_grant.py
index f8d77fc9..6d437e2c 100644
--- a/tests/flask/test_oauth2/test_authorization_code_grant.py
+++ b/tests/flask/test_oauth2/test_authorization_code_grant.py
@@ -352,3 +352,47 @@ def test_token_generator(app, test_client, client, server):
     resp = json.loads(rv.data)
     assert "access_token" in resp
     assert "c-authorization_code.1." in resp["access_token"]
+
+
+def test_missing_scope_empty_default(test_client, client, monkeypatch):
+    """When client.get_allowed_scope() returns empty string for missing scope,
+    the authorization should proceed without a scope.
+    """
+
+    def get_allowed_scope_empty(scope):
+        if scope is None:
+            return ""
+        return scope
+
+    monkeypatch.setattr(client, "get_allowed_scope", get_allowed_scope_empty)
+
+    rv = test_client.post(authorize_url, data={"user_id": "1"})
+    assert "code=" in rv.location
+
+    params = dict(url_decode(urlparse.urlparse(rv.location).query))
+    code = params["code"]
+    headers = create_basic_header("client-id", "client-secret")
+    rv = test_client.post(
+        "/oauth/token",
+        data={
+            "grant_type": "authorization_code",
+            "code": code,
+        },
+        headers=headers,
+    )
+    resp = json.loads(rv.data)
+    assert "access_token" in resp
+    assert resp.get("scope", "") == ""
+
+
+def test_unsupported_response_type_does_not_redirect(test_client):
+    """Regression test for open redirect via unsupported response_type."""
+    url = (
+        "/oauth/authorize"
+        "?response_type=totally-unsupported"
+        "&redirect_uri=https%3A%2F%2Fevil.example%2Flanding"
+        "&state=s1"
+    )
+    rv = test_client.get(url)
+    assert rv.status_code == 400
+    assert rv.headers.get("Location") is None

From ef09aebbba4439dedb22bd15777d1b3458b6f0ab Mon Sep 17 00:00:00 2001
From: Hsiaoming Yang <me@lepture.com>
Date: Mon, 13 Apr 2026 22:29:14 +0900
Subject: [PATCH 08/12] chore: release 1.6.10

---
 authlib/consts.py  | 2 +-
 docs/changelog.rst | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/authlib/consts.py b/authlib/consts.py
index ed67bccf..1fc26196 100644
--- a/authlib/consts.py
+++ b/authlib/consts.py
@@ -1,5 +1,5 @@
 name = "Authlib"
-version = "1.6.9"
+version = "1.6.10"
 author = "Hsiaoming Yang <me@lepture.com>"
 homepage = "https://authlib.org"
 default_user_agent = f"{name}/{version} (+{homepage})"
diff --git a/docs/changelog.rst b/docs/changelog.rst
index c35a911b..2cdab361 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -9,7 +9,7 @@ Here you can see the full list of changes between each Authlib release.
 Version 1.6.10
 --------------
 
-**Unreleased**
+**Released on Apr 13, 2026**
 
 - Fix redirecting to unvalidated ``redirect_uri`` on ``UnsupportedResponseTypeError``.
 

From 401a7709c3fe43bce1b2105d16a475b688faa788 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89loi=20Rivard?= <eloi@yaal.coop>
Date: Wed, 15 Apr 2026 09:42:04 +0200
Subject: [PATCH 09/12] fix: CSRF issue with starlette client

---
 authlib/integrations/starlette_client/apps.py | 17 ++----
 .../starlette_client/integration.py           | 14 ++++-
 docs/changelog.rst                            |  8 +++
 .../test_starlette/test_oauth_client.py       | 60 +++++++++++++++++++
 4 files changed, 85 insertions(+), 14 deletions(-)

diff --git a/authlib/integrations/starlette_client/apps.py b/authlib/integrations/starlette_client/apps.py
index b97143cf..c69e838d 100644
--- a/authlib/integrations/starlette_client/apps.py
+++ b/authlib/integrations/starlette_client/apps.py
@@ -14,11 +14,7 @@ class StarletteAppMixin:
     async def save_authorize_data(self, request, **kwargs):
         state = kwargs.pop("state", None)
         if state:
-            if self.framework.cache:
-                session = None
-            else:
-                session = request.session
-            await self.framework.set_state_data(session, state, kwargs)
+            await self.framework.set_state_data(request.session, state, kwargs)
         else:
             raise RuntimeError("Missing state value")
 
@@ -80,13 +76,10 @@ async def authorize_access_token(self, request, **kwargs):
                     "state": form.get("state"),
                 }
 
-        if self.framework.cache:
-            session = None
-        else:
-            session = request.session
-
-        state_data = await self.framework.get_state_data(session, params.get("state"))
-        await self.framework.clear_state_data(session, params.get("state"))
+        state_data = await self.framework.get_state_data(
+            request.session, params.get("state")
+        )
+        await self.framework.clear_state_data(request.session, params.get("state"))
         params = self._format_state_params(state_data, params)
 
         claims_options = kwargs.pop("claims_options", None)
diff --git a/authlib/integrations/starlette_client/integration.py b/authlib/integrations/starlette_client/integration.py
index 25b7fdbc..db3639b6 100644
--- a/authlib/integrations/starlette_client/integration.py
+++ b/authlib/integrations/starlette_client/integration.py
@@ -22,6 +22,10 @@ async def get_state_data(
     ) -> dict[str, Any]:
         key = f"_state_{self.name}_{state}"
         if self.cache:
+            # require a session-bound marker to prove the callback originates
+            # from the user-agent that started the flow (RFC 6749 §10.12)
+            if session is None or session.get(key) is None:
+                return None
             value = await self._get_cache_data(key)
         elif session is not None:
             value = session.get(key)
@@ -37,21 +41,27 @@ async def set_state_data(
     ):
         key_prefix = f"_state_{self.name}_"
         key = f"{key_prefix}{state}"
+        now = time.time()
         if self.cache:
             await self.cache.set(key, json.dumps({"data": data}), self.expires_in)
+            if session is not None:
+                # clear old state data to avoid session size growing
+                for old_key in list(session.keys()):
+                    if old_key.startswith(key_prefix):
+                        session.pop(old_key)
+                session[key] = {"exp": now + self.expires_in}
         elif session is not None:
             # clear old state data to avoid session size growing
             for old_key in list(session.keys()):
                 if old_key.startswith(key_prefix):
                     session.pop(old_key)
-            now = time.time()
             session[key] = {"data": data, "exp": now + self.expires_in}
 
     async def clear_state_data(self, session: Optional[dict[str, Any]], state: str):
         key = f"_state_{self.name}_{state}"
         if self.cache:
             await self.cache.delete(key)
-        elif session is not None:
+        if session is not None:
             session.pop(key, None)
             self._clear_session_state(session)
 
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 2cdab361..34ffc38f 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -6,6 +6,14 @@ Changelog
 
 Here you can see the full list of changes between each Authlib release.
 
+Version 1.6.11
+--------------
+
+**Released on Apr 15, 2026**
+
+- Fix CSRF vulnerability in the Starlette OAuth client when a ``cache`` is
+  configured.
+
 Version 1.6.10
 --------------
 
diff --git a/tests/clients/test_starlette/test_oauth_client.py b/tests/clients/test_starlette/test_oauth_client.py
index 74729710..5f5a909a 100644
--- a/tests/clients/test_starlette/test_oauth_client.py
+++ b/tests/clients/test_starlette/test_oauth_client.py
@@ -118,6 +118,66 @@ async def test_oauth2_authorize():
     assert token["access_token"] == "a"
 
 
+class _FakeAsyncCache:
+    """Minimal async cache implementing the authlib framework cache protocol."""
+
+    def __init__(self):
+        self.store = {}
+
+    async def get(self, key):
+        return self.store.get(key)
+
+    async def set(self, key, value, expires=None):
+        self.store[key] = value
+
+    async def delete(self, key):
+        self.store.pop(key, None)
+
+
+@pytest.mark.asyncio
+async def test_oauth2_authorize_csrf_with_cache():
+    """When a cache is configured, the state must still be bound to the
+    session that initiated the flow. Otherwise an attacker can start an
+    authorization request, stop before the callback, and trick a victim into
+    completing the flow — logging the victim into the attacker's account
+    (RFC 6749 §10.12)."""
+    transport = ASGITransport(
+        AsyncPathMapDispatch({"/token": {"body": get_bearer_token()}})
+    )
+    oauth = OAuth(cache=_FakeAsyncCache())
+    client = oauth.register(
+        "dev",
+        client_id="dev",
+        client_secret="dev",
+        api_base_url="https://resource.test/api",
+        access_token_url="https://provider.test/token",
+        authorize_url="https://provider.test/authorize",
+        client_kwargs={
+            "transport": transport,
+        },
+    )
+
+    # Attacker initiates an auth flow from their own session.
+    attacker_req = Request({"type": "http", "session": {}})
+    resp = await client.authorize_redirect(attacker_req, "https://client.test/callback")
+    assert resp.status_code == 302
+    url = resp.headers.get("Location")
+    state = dict(url_decode(urlparse.urlparse(url).query))["state"]
+
+    # Victim is tricked into hitting the callback URL. The victim's browser
+    # carries a *different* session — they never initiated this flow.
+    victim_req = Request(
+        {
+            "type": "http",
+            "path": "/",
+            "query_string": f"code=a&state={state}".encode(),
+            "session": {},
+        }
+    )
+    with pytest.raises(OAuthError):
+        await client.authorize_access_token(victim_req)
+
+
 @pytest.mark.asyncio
 async def test_oauth2_authorize_access_denied():
     oauth = OAuth()

From 0dc0e5b4dc84f155319518a3732113af6fa47525 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89loi=20Rivard?= <eloi@yaal.coop>
Date: Thu, 16 Apr 2026 09:17:54 +0200
Subject: [PATCH 10/12] chore: bump to 1.6.11

---
 authlib/consts.py  | 2 +-
 docs/changelog.rst | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/authlib/consts.py b/authlib/consts.py
index 1fc26196..38d259d3 100644
--- a/authlib/consts.py
+++ b/authlib/consts.py
@@ -1,5 +1,5 @@
 name = "Authlib"
-version = "1.6.10"
+version = "1.6.11"
 author = "Hsiaoming Yang <me@lepture.com>"
 homepage = "https://authlib.org"
 default_user_agent = f"{name}/{version} (+{homepage})"
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 34ffc38f..799a6502 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -9,7 +9,7 @@ Here you can see the full list of changes between each Authlib release.
 Version 1.6.11
 --------------
 
-**Released on Apr 15, 2026**
+**Released on Apr 16, 2026**
 
 - Fix CSRF vulnerability in the Starlette OAuth client when a ``cache`` is
   configured.

From 9babc131e13b018a267ae78747cba7caa6dfb7d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89loi=20Rivard?= <eloi@yaal.coop>
Date: Sat, 2 May 2026 17:56:03 +0200
Subject: [PATCH 11/12] fix: redirecting to unvalidated redirect_uri on
 InvalidScopeError in OIDC grants

---
 authlib/oidc/core/grants/hybrid.py              | 15 ++++++++-------
 authlib/oidc/core/grants/implicit.py            |  4 ++--
 docs/changelog.rst                              |  8 ++++++++
 .../test_oauth2/test_openid_hybrid_grant.py     | 17 +++++++++++++++++
 .../test_oauth2/test_openid_implict_grant.py    | 17 +++++++++++++++++
 5 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/authlib/oidc/core/grants/hybrid.py b/authlib/oidc/core/grants/hybrid.py
index 8c373525..c3605eb8 100644
--- a/authlib/oidc/core/grants/hybrid.py
+++ b/authlib/oidc/core/grants/hybrid.py
@@ -49,19 +49,20 @@ def save_authorization_code(self, code, request):
         raise NotImplementedError()
 
     def validate_authorization_request(self):
-        if not is_openid_scope(self.request.payload.scope):
-            raise InvalidScopeError(
-                "Missing 'openid' scope",
-                redirect_uri=self.request.payload.redirect_uri,
-                redirect_fragment=True,
-            )
         self.register_hook(
             "after_validate_authorization_request_payload",
             lambda grant, redirect_uri: validate_nonce(
                 grant.request, grant.exists_nonce, required=True
             ),
         )
-        return validate_code_authorization_request(self)
+        redirect_uri = validate_code_authorization_request(self)
+        if not is_openid_scope(self.request.payload.scope):
+            raise InvalidScopeError(
+                "Missing 'openid' scope",
+                redirect_uri=redirect_uri,
+                redirect_fragment=True,
+            )
+        return redirect_uri
 
     def create_granted_params(self, grant_user):
         self.request.user = grant_user
diff --git a/authlib/oidc/core/grants/implicit.py b/authlib/oidc/core/grants/implicit.py
index fc76371f..aacdf865 100644
--- a/authlib/oidc/core/grants/implicit.py
+++ b/authlib/oidc/core/grants/implicit.py
@@ -82,13 +82,13 @@ def get_audiences(self, request):
         return [client.get_client_id()]
 
     def validate_authorization_request(self):
+        redirect_uri = super().validate_authorization_request()
         if not is_openid_scope(self.request.payload.scope):
             raise InvalidScopeError(
                 "Missing 'openid' scope",
-                redirect_uri=self.request.payload.redirect_uri,
+                redirect_uri=redirect_uri,
                 redirect_fragment=True,
             )
-        redirect_uri = super().validate_authorization_request()
         try:
             validate_nonce(self.request, self.exists_nonce, required=True)
         except OAuth2Error as error:
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 799a6502..46f7dced 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -6,6 +6,14 @@ Changelog
 
 Here you can see the full list of changes between each Authlib release.
 
+Version 1.6.12
+--------------
+
+**Unreleased**
+
+- Fix redirecting to unvalidated ``redirect_uri`` on ``InvalidScopeError``
+  in ``OpenIDImplicitGrant`` and ``OpenIDHybridGrant``.
+
 Version 1.6.11
 --------------
 
diff --git a/tests/flask/test_oauth2/test_openid_hybrid_grant.py b/tests/flask/test_oauth2/test_openid_hybrid_grant.py
index 5aeb3726..15ac1f6c 100644
--- a/tests/flask/test_oauth2/test_openid_hybrid_grant.py
+++ b/tests/flask/test_oauth2/test_openid_hybrid_grant.py
@@ -160,6 +160,23 @@ def test_invalid_scope(test_client):
     assert "error=invalid_scope" in rv.location
 
 
+def test_missing_openid_in_scope_does_not_redirect_to_unregistered_uri(test_client):
+    """An unregistered redirect_uri must not be followed even when openid scope is missing."""
+    rv = test_client.post(
+        "/oauth/authorize",
+        data={
+            "client_id": "client-id",
+            "response_type": "code id_token",
+            "state": "s",
+            "nonce": "n",
+            "scope": "profile",
+            "redirect_uri": "https://evil.example.com/phish",
+        },
+    )
+    assert rv.status_code == 400
+    assert rv.headers.get("Location") is None
+
+
 def test_access_denied(test_client):
     rv = test_client.post(
         "/oauth/authorize",
diff --git a/tests/flask/test_oauth2/test_openid_implict_grant.py b/tests/flask/test_oauth2/test_openid_implict_grant.py
index 1a24d51a..3806466b 100644
--- a/tests/flask/test_oauth2/test_openid_implict_grant.py
+++ b/tests/flask/test_oauth2/test_openid_implict_grant.py
@@ -107,6 +107,23 @@ def test_missing_openid_in_scope(test_client):
     assert "error=invalid_scope" in rv.location
 
 
+def test_missing_openid_in_scope_does_not_redirect_to_unregistered_uri(test_client):
+    """An unregistered redirect_uri must not be followed even when openid scope is missing."""
+    rv = test_client.post(
+        "/oauth/authorize",
+        data={
+            "response_type": "id_token token",
+            "client_id": "client-id",
+            "scope": "profile",
+            "state": "s",
+            "nonce": "n",
+            "redirect_uri": "https://evil.example.com/phish",
+        },
+    )
+    assert rv.status_code == 400
+    assert rv.headers.get("Location") is None
+
+
 def test_denied(test_client):
     rv = test_client.post(
         "/oauth/authorize",

From e46e515b3a87ea63ab0606b248d75f69d83a2391 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89loi=20Rivard?= <eloi@yaal.coop>
Date: Mon, 4 May 2026 10:07:39 +0200
Subject: [PATCH 12/12] chore: bump to 1.6.12

---
 authlib/consts.py  | 2 +-
 docs/changelog.rst | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/authlib/consts.py b/authlib/consts.py
index 38d259d3..de771c1c 100644
--- a/authlib/consts.py
+++ b/authlib/consts.py
@@ -1,5 +1,5 @@
 name = "Authlib"
-version = "1.6.11"
+version = "1.6.12"
 author = "Hsiaoming Yang <me@lepture.com>"
 homepage = "https://authlib.org"
 default_user_agent = f"{name}/{version} (+{homepage})"
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 46f7dced..e6cc6ee4 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -9,7 +9,7 @@ Here you can see the full list of changes between each Authlib release.
 Version 1.6.12
 --------------
 
-**Unreleased**
+**Released on may 4, 2026**
 
 - Fix redirecting to unvalidated ``redirect_uri`` on ``InvalidScopeError``
   in ``OpenIDImplicitGrant`` and ``OpenIDHybridGrant``.