[Triage] [uwsgi] InvalidUWSGIHeader: incomplete header when using gevent or gthread workers

[Jean-Daniel]

Type

Bug Report

Description

When deploying a Django app in production with nginx and uwsgi_pass, I got a lot of errors from gunicorn like this one:

Traceback (most recent call last):
  File "/app/.venv/lib/python3.14/site-packages/gunicorn/workers/base_async.py", line 61, in handle
    req = next(parser)
  File "/app/.venv/lib/python3.14/site-packages/gunicorn/http/parser.py", line 56, in __next__
    self.mesg = self.mesg_class(self.cfg, self.unreader, self.source_addr, self.req_count)
                ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib/python3.14/site-packages/gunicorn/uwsgi/message.py", line 68, in __init__
    unused = self.parse(self.unreader)
  File "/app/.venv/lib/python3.14/site-packages/gunicorn/uwsgi/message.py", line 96, in parse
    raise InvalidUWSGIHeader("incomplete header")
gunicorn.uwsgi.errors.InvalidUWSGIHeader: Invalid uWSGI header: incomplete header

[5] [ERROR] Error handling request (no URI read)

When switching to sync worker mode, there is no error, but this is not an acceptable workaround for a production server.

It may be related to #3207 but this is not the exact same issue, as it does not involve timeout and is when using uwsgi.

Steps to Reproduce (for bugs)

Create a simple app
Deploy behind nginx with mod_uwsgi
Run using gunicorn gevent worker
Make some requests to nginx.

Configuration

protocol = "uwsgi"

workers = 2
worker_class = "gevent"
worker_connections = 512

Logs / Error Output

No response

Gunicorn Version

gunicorn 25.1.0

Python Version

Python 3.14

Worker Class

gevent

Operating System

python:3.14-slim docker image

Additional Context

No response

Checklist

• I have searched existing discussions and issues for duplicates
• I have checked the documentation and FAQ