twisted.web has disordered HTTP pipeline response

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2023-46137: 0.88% estimated exploitation activity in the next 30 days; percentile 59.13 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Twisted is an event-based framework for internet applications. Prior to version 23.10.0rc1, when sending multiple HTTP requests in one TCP packet, twisted.web will process the requests asynchronously without guaranteeing the response order. If one of the endpoints is controlled by an attacker, the attacker can delay the response on purpose to manipulate the response of the second request when a victim launched two requests using HTTP pipeline. Version 23.10.0rc1 contains a patch for this issue. Details There's an example faulty program: When two requests for /first and /second are sent in the same order, the second request will be responded to first.

Published by the source

25 Oct 2023, 21:15 UTC

Last modified by the source

4 Nov 2025, 17:02 UTC

Source last checked

26 Oct 2026, 13:35 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-xc8x-vp79-p3wm

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-xc8x-vp79-p3wm

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# Patch Next advisory brief: CVE-2023-46137

Advisory: twisted.web has disordered HTTP pipeline response
IDs: CVE-2023-46137, GHSA-xc8x-vp79-p3wm
Record: https://patchnext.com/advisories/cve-2023-46137 (revision 3, source checked 26 Oct 2026, 13:35 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: twisted 23.10.0rc1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI twisted: affected < 23.10.0rc1; fixed in 23.10.0rc1

## Suggested inspection (read-only)
- `python -m pip show twisted`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on twisted.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-xc8x-vp79-p3wm (OSV record GHSA-xc8x-vp79-p3wm lists affected ranges: PyPI twisted >=0 <23.10.0rc1 (fixed))
- Verified: https://github.com/advisories/GHSA-xc8x-vp79-p3wm (GitHub-reviewed advisory GHSA-xc8x-vp79-p3wm lists affected ranges: PyPI twisted >=0 <23.10.0rc1)

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