Cant login anymore: password cannot be longer than 72 bytes

[Y0ngg4n]

Description

I can not login into my account anymore. My password is very long.

Steps to reproduce

• try to login into my synapse instance

Homeserver

matrixchat.org

Synapse Version

v1.140.0

Installation Method

Docker (matrixdotorg/synapse)

Database

singe postgresql server

Workers

Single process

Platform

Kubernetes deployment

Configuration

No response

Relevant log output

ValueError: password cannot be longer than 72 bytes, truncate manually if necessary (e.g. my_password[:72])
2025-12-20 16:54:52,260 - synapse.http.server - 151 - ERROR - POST-114 - Failed handle request via 'LoginRestServlet': <XForwardedForRequest at 0x7ff25e3568d0 method='POST' uri='/_matrix/client/v3/login' clientproto='HTTP/1.1' site='8008'>
Traceback (most recent call last):
  File "/usr/local/lib/python3.12/site-packages/synapse/http/server.py", line 339, in _async_render_wrapper
    callback_return = await self._async_render(request)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/http/server.py", line 582, in _async_render
    callback_return = await raw_callback_return
                      ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/rest/client/login.py", line 262, in on_POST
    result = await self._do_other_login(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/rest/client/login.py", line 357, in _do_other_login
    canonical_user_id, callback = await self.auth_handler.validate_login(
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/handlers/auth.py", line 1288, in validate_login
    return await self._validate_userid_login(username, login_submission)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/handlers/auth.py", line 1377, in _validate_userid_login
    canonical_user_id = await self._check_local_password(
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/handlers/auth.py", line 1437, in _check_local_password
    result = await self.validate_hash(password, password_hash)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/handlers/auth.py", line 1719, in validate_hash
    return await defer_to_thread(
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/twisted/internet/defer.py", line 1187, in __iter__
    yield self
  File "/usr/local/lib/python3.12/site-packages/twisted/python/threadpool.py", line 269, in inContext
    result = inContext.theWork()  # type: ignore[attr-defined]
             ^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/twisted/python/threadpool.py", line 285, in <lambda>
    inContext.theWork = lambda: context.call(  # type: ignore[attr-defined]
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/twisted/python/context.py", line 117, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/twisted/python/context.py", line 82, in callWithContext
    return func(*args, **kw)
           ^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/logging/context.py", line 1169, in g
    return f(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/synapse/handlers/auth.py", line 1710, in _do_validate_hash
    return bcrypt.checkpw(
           ^^^^^^^^^^^^^^^
ValueError: password cannot be longer than 72 bytes, truncate manually if necessary (e.g. my_password[:72])

Anything else that would be useful to know?

No response