AttributeError: 'AppContext' object has no attribute 'expired_jwt'

After updating from 3.15 to 3.16 or greater, an expired token will throw the following error:

Traceback (most recent call last):
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/app.py", line 2309, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/app.py", line 2295, in wsgi_app
    response = self.handle_exception(e)
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/app.py", line 1741, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask/app.py", line 1719, in handle_user_exception
    return handler(e)
  File "/Users/user/path/to/venv/lib/python3.7/site-packages/flask_jwt_extended/jwt_manager.py", line 99, in handle_expired_error
    token = ctx_stack.top.expired_jwt
AttributeError: 'AppContext' object has no attribute 'expired_jwt'

        @app.errorhandler(ExpiredSignatureError)
        def handle_expired_error(e):
            try:
                token = ctx_stack.top.expired_jwt #<--- explodes here
                return self._expired_token_callback(token)
            except TypeError:
                msg = (
                    "jwt.expired_token_loader callback now takes the expired token "
                    "as an additional paramter. Example: expired_callback(token)"
                )
                warn(msg, DeprecationWarning)
                return self._expired_token_callback()

I do not have a custom expired_token_loader so I’m using the default one (default_expired_token_callback)

[vimalloc]

The fix is released in version 3.18.1.

Cheers!

[xolott]

I figured out what was causing my exception, it is a call to the method decode_token on the before_request flask’s hook. This is my minimal, complete, and verifiable example based on the the one from this project docs:

from flask import Flask, jsonify, request, g
from flask_jwt_extended import (
    JWTManager,
    jwt_required,
    create_access_token,
    get_jwt_identity,
    decode_token,
)

app = Flask(__name__)

# Setup the Flask-JWT-Extended extension
app.config["JWT_SECRET_KEY"] = "super-secret"  # Change this!
app.config["JWT_ACCESS_TOKEN_EXPIRES"] = 5
jwt = JWTManager(app)


@app.before_request
def _get_token():
    auth_header = request.headers.get("Authorization")
    g.token = None
    if auth_header and "Bearer" in auth_header:
        jwt_token = auth_header.split(" ")[-1]
        g.token = decode_token(jwt_token)


# Provide a method to create access tokens. The create_access_token()
# function is used to actually generate the token, and you can return
# it to the caller however you choose.
@app.route("/login", methods=["POST"])
def login():
    if not request.is_json:
        return jsonify({"msg": "Missing JSON in request"}), 400

    username = request.json.get("username", None)
    password = request.json.get("password", None)
    if not username:
        return jsonify({"msg": "Missing username parameter"}), 400
    if not password:
        return jsonify({"msg": "Missing password parameter"}), 400

    if username != "test" or password != "test":
        return jsonify({"msg": "Bad username or password"}), 401

    # Identity can be any data that is json serializable
    access_token = create_access_token(identity=username)
    return jsonify(access_token=access_token), 200


# Protect a view with jwt_required, which requires a valid access token
# in the request to access.
@app.route("/protected", methods=["GET"])
@jwt_required
def protected():
    # Access the identity of the current user with get_jwt_identity
    current_user = get_jwt_identity()
    return jsonify(logged_in_as=current_user), 200


if __name__ == "__main__":
    app.run()

After making a request to the /protected endpoint, prints:

...
site-packages/flask_jwt_extended/jwt_manager.py", line 99, in handle_expired_error
    token = ctx_stack.top.expired_jwt
AttributeError: 'AppContext' object has no attribute 'expired_jwt'

Env:

• Python 3.6.7 (virtual env with pipenv)
• Ubuntu 18.04.2

Dependencies

• flask 1.0.2
• flask-jwt-extended 3.18.0