Advisory record · GHSA-hc5x-x2vx-497g

Gunicorn HTTP Request/Response Smuggling vulnerability

CVSS 7.5 HighEPSS 0.0081 · 56th percentile

Published by the GitHub Advisory Database at 20 Mar 2025, 12:32 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
gunicornPyPI<22.0.022.0.0
Identifiers
GHSA-hc5x-x2vx-497g · CVE-2024-6827 · PYSEC-2026-1433
Weakness (CWE)
CWE-444
Published
20 Mar 2025
Updated
10 Sept 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Gunicorn versions before 22.0.0 do not properly validate the Transfer-Encoding header, so requests can be handled using Content-Length instead, enabling TE.CL request smuggling. An attacker who can send HTTP requests through a proxy or front-end in front of Gunicorn could smuggle requests, which may enable cache poisoning, session manipulation, or security bypass. Upgrade to gunicorn 22.0.0 or later. The source gives few details on specific exploitation conditions.

Written 5 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
7.5 High 3.0 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CNA (@huntr_ai)
  • CISA KEV Not listed.
  • EPSS 0.0081, the 56th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:37 UTC First seen by agentprime
  2. 31 Oct 2026, 14:37 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.