Changelog - 2026¶

24.1.1 - 2026-01-24¶

Fix forwarded_allow_ips and proxy_allow_ips to remain as strings for backward compatibility with external tools like uvicorn. Network validation now uses strict mode to detect invalid CIDR notation (e.g., 192.168.1.1/24 where host bits are set) (#3458, PR #3459)

Official Docker Image: Gunicorn now publishes official Docker images to GitHub Container Registry at ghcr.io/benoitc/gunicorn
Based on Python 3.12 slim image
Uses recommended worker formula (2 × CPU + 1)
Configurable via environment variables
PROXY Protocol v2 Support: Extended PROXY protocol implementation to support the binary v2 format in addition to the existing text-based v1 format (PR #3451)
New --proxy-protocol modes: off, v1, v2, auto
auto mode (default when enabled) detects v1 or v2 automatically
v2 binary format is more efficient and supports additional metadata
Works with HAProxy, AWS NLB/ALB, and other PROXY protocol v2 sources
CIDR Network Support: --forwarded-allow-ips and --proxy-allow-from now accept CIDR notation (e.g., 192.168.0.0/16) for specifying trusted networks (PR #3449)
Socket Backlog Metric: New gunicorn.socket.backlog gauge metric reports the current socket backlog size on Linux systems (PR #3450)
InotifyReloader Enhancement: The inotify-based reloader now watches newly imported modules, not just those loaded at startup (PR #3447)

Fix signal handling regression where SIGCLD alias caused "Unhandled signal: cld" errors on Linux when workers fail during boot (#3453)
Fix socket blocking mode on keepalive connections preventing SSL handshake failures with async workers (PR #3452)
Use smaller buffer size in finish_body() for faster timeout detection on slow or abandoned connections (PR #3453)
Handle SSLWantReadError in finish_body() to prevent worker hangs during SSL renegotiation (PR #3448)
Log SIGTERM as info level instead of warning to reduce noise in orchestrated environments (PR #3446)
Print exception details to stderr when worker fails to boot (PR #3443)
Fix unreader.unread() to prepend data to buffer instead of appending (PR #3442)
Prevent RecursionError when pickling Config objects (PR #3441)
Use proper exception chaining with raise from in glogging.py (PR #3440)

ASGI Worker (Beta): Native asyncio-based ASGI support for running async Python frameworks like FastAPI, Starlette, and Quart without external dependencies (PR #3444)
HTTP/1.1 with keepalive connections
WebSocket support
Lifespan protocol for startup/shutdown hooks
Optional uvloop for improved performance
New settings: --asgi-loop, --asgi-lifespan, --root-path
uWSGI Binary Protocol: Support for receiving requests from nginx via uwsgi_pass directive, enabling efficient binary protocol communication (PR #3444)
New settings: --protocol uwsgi, --uwsgi-allow-from
Documentation Migration: Migrated documentation from Sphinx to MkDocs with Material theme for improved navigation and mobile experience (PR #3426)

eventlet: Require eventlet >= 0.40.3 to address CVE-2021-21419 (websocket memory exhaustion) and CVE-2025-58068 (HTTP request smuggling) (PR #3445)
gevent: Require gevent >= 24.10.1 to address CVE-2023-41419 (HTTP request smuggling) and CVE-2024-3219 (socket.socketpair vulnerability) (PR #3445)
tornado: Require tornado >= 6.5.0 to address CVE-2025-47287 (HTTP request smuggling) and other security fixes (PR #3445)

ASGI Worker Beta

The ASGI worker is a beta feature. While tested, the API and behavior may change in future releases. Please report any issues on GitHub.