gunicorn 26.1.0

New Features

• Glob patterns in reload_extra_files: entries containing *, ? or [
  are treated as patterns, so ui/*/config.json watches every view's config
  without listing them one by one. Patterns are re-expanded on every reload
  check rather than once at startup, so a file created later starts being
  watched without restarting gunicorn, and ** recurses. A pattern matching
  nothing warns instead of failing, since with live expansion it may match later
  (#1643,
  #3662).

Security

• Dependency floors raised past known advisories: every declared floor was
  checked against the advisory database. tornado, h2, setuptools and
  pymdown-extensions permitted vulnerable versions and now require the first
  clean release; pytest and httpx were unpinned and now carry floors. The
  tornado example pinned tornado<6, which was both the source of several
  advisories and older than the >=6.5.0 the tornado worker needs, so the
  example could not run as pinned.

Bug Fixes

• SIGHUP did not reload the logger configuration: Arbiter.reload()
  re-read the configuration file but kept using the logger built at startup,
  calling only reopen_files() on its existing handlers. Changes to
  logconfig, logconfig_dict, logconfig_json and loglevel were ignored
  until a full restart, which in containers meant replacing the pod. The
  existing logger now re-runs its setup on reload, so new handlers, formats
  and levels take effect while the process identity and its listeners are
  preserved, and re-running the setup no longer stacks duplicate syslog
  handlers. An invalid log configuration on reload is not fatal either: the
  error is reported on stderr, the previous working configuration is restored
  and the master keeps running with it
  (#3353).

• Truncated chunked bodies accepted: RFC 9112 section 7.1.2 ends a chunked
  body with 0 CRLF CRLF, the second CRLF being the mandatory empty trailer
  section. ChunkedReader.parse_chunk_size() swallowed the NoMoreData raised
  while scanning for it, so a body cut short right after the last chunk line was
  treated as complete instead of rejected. It now raises
  ChunkMissingTerminator
  (#3382,
  #3685).

• --spew crashed on dynamically generated code: the trace hook indexed the
  2-tuple returned by inspect.getsourcelines() by line number rather than
  indexing the list of lines, so a frame with no __file__ raised
  AttributeError: 'int' object has no attribute 'rstrip' on line 1 and
  IndexError beyond it. The tuple is now unpacked and offset by the source's
  starting line (#3344,
  #3495).

• Duplicate Host and Content-Type headers accepted: RFC 9110 section 5.3
  allows only one of each, and a repeat cannot be merged into a list, so the
  message means different things to gunicorn and to anything downstream. Both
  are now rejected with InvalidHeader. The check lives in the policy hook
  shared by both parsers, so the pure-Python and fast parsers agree. Duplicate
  Content-Length was already rejected and is unchanged
  (#3366,
  #3548).

• Non-worker children reported as failed workers: reap_workers() reaps
  every child through waitpid(-1), including processes the kernel reparented
  onto gunicorn when it runs as PID 1 in a container, but it logged the exit
  status before checking whether the pid was ever a worker. An unrelated process
  produced Worker (pid:N) exited with code M and triggered alerts. More
  seriously, such a process exiting with code 3 or 4 raised HaltServer and shut
  the server down. Ownership is now established first: the dirty arbiter is
  reported as itself, unknown children are reaped silently at debug level, and
  only real workers can halt the server
  (#3220,
  #3566).

• Dirty arbiter exits were invisible on SIGCHLD: handle_chld() called
  reap_workers() first, whose waitpid(-1) claimed the dirty arbiter before
  reap_dirty_arbiter() could identify it, so the latter always hit ECHILD and
  its reporting never ran. The dirty arbiter is now reaped first, and
  reap_workers() recognises it if it exits mid-loop.

• Dirty arbiter returned stale responses after a worker timeout: when a
  request reached dirty_timeout the arbiter answered the client with a timeout
  error but kept the worker connection open. The worker's late response was then
  the first message waiting on that socket, so the next request routed to the
  same worker received the previous request's result, and every request after it
  stayed one response behind. The connection is now closed on timeout, so the
  late answer is discarded with it
  (#3626).

• ASGI connection count leaked on server-initiated close: nr_conns was
  only decremented in connection_lost(), behind a guard keyed on the same
  flag _close_transport() sets first. Every close the server started (a
  Connection: close response, a keepalive timeout, an error abort) leaked one
  count, so ASGIWorker._shutdown() ran the full graceful_timeout and warned
  about connections that were already gone. The guard now uses its own flag, so
  the decrement and the rest of the cleanup run exactly once whichever side
  closes first (#3661).

• Inotify reloader on cwd-relative extra files: reload_extra_files entries
  with no directory part (for example .env) produced an empty dirname, and
  watching it raised InotifyError with ENOENT. The current directory is now
  watched as . (#3377,
  #3667).

• StatsD zero-valued metrics: gauges, counters, histograms and timers
  reporting 0 were silently dropped because the value was tested for
  truthiness. Only None is skipped now
  (#3676).

• Spurious no-body warning from sendfile(): a HEAD, 204 or 304 response
  served through sendfile() warned about dropped body bytes even when the
  file was empty and nothing was dropped. It now warns only when there are
  bytes to drop, matching write()
  (#3684).

• Bare except in the gevent websocket example: narrowed to
  except Exception (#3683).

• ASGI receive() cancellation: Let asyncio.CancelledError propagate
  from BodyReceiver instead of swallowing it and returning
  http.disconnect. Frameworks that cancel their disconnect listener after
  the response completes (Django) no longer see the cancel masked, so
  request_finished fires and close_old_connections() runs. Fixes idle
  database connections leaking since 25.1.0
  (#3627,
  #3654).

• Control socket leak on SIGHUP reload: The control thread is now marked
  ready once its loop and server are live, and the stop paths wait on that
  readiness before scheduling shutdown. Reloads no longer leak one thread and
  its selector fd plus unix socket per worker, which eventually raised
  "too many open files"
  (#3648).

• WSGI body framing on HEAD/1xx/204/304: Mirror the ASGI strip-and-warn
  behavior on the WSGI path. Content-Length is stripped on 1xx/204 per
  RFC 9110 section 6.4.2, body bytes are dropped for no-body responses in
  both write() and sendfile(), and a single warning is logged per request
  (#3413).

Refactoring

• Pass log arguments to the logger instead of pre-formatting the worker
  termination message in Arbiter.reap_workers()
  (#3678).

Changes

• packaging is no longer a runtime dependency: it was only ever imported by
  the gevent worker, to compare gevent's version. It moved to the gevent and
  testing extras, so a plain pip install gunicorn pulls in nothing
  (#3643).

• Fast HTTP Parser: Require gunicorn_h1c >= 0.6.6, which rejects duplicate
  Host and Content-Type headers in the C parser itself. Gunicorn already
  refuses them on both the WSGI and ASGI paths, so this changes nothing that is
  reachable; it moves the rejection to where the bytes are read and lets the
  ASGI corpus exercise those cases against the fast parser directly.

Full changelog: https://gunicorn.org/2026-news/