---
id: CVE-2026-84382
title: HTTPX2 is a next generation HTTP client for Python
summary: >-
  HTTPX2 is a next generation HTTP client for Python. Prior to 2.12.0, the
  HTTPX2 content decoders in src/httpx2/httpx2/_decoders.py fully inflate each
  gzip, deflate, br, or zstd network chunk before iter_bytes() or aiter_bytes()
  yields bo…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-409
vendor: httpx2
product: httpx2
affected:
  - httpx2 < 2.12.0
patched:
  - httpx2 2.12.0
published: '2026-09-02'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:05:23.237'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84382'
references:
  - url: >-
      https://github.com/pydantic/httpx2/commit/4fd0c70a3f207c618b145934792f791bccfb39f8
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/pull/1126'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/releases/tag/v2.12.0'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/security/advisories/GHSA-8xx6-hgc6-gc2m'
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84382'
  - url: 'https://github.com/pydantic/httpx2'
  - url: 'https://github.com/advisories/GHSA-8xx6-hgc6-gc2m'
  - url: 'https://pypi.org/project/httpx2'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84382.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-84382'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2527702'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-84382'
tags:
  - nvd
  - osv
  - pip
  - ghsa
  - csaf
  - vex
  - red-hat
epss: 0.0063
epssPercentile: 0.47957
aliases:
  - GHSA-8xx6-hgc6-gc2m
  - PYSEC-2026-3846
ecosystem: pip
ingestedAt: '2026-09-08T21:11:12.322Z'
---

## Overview

HTTPX2 is a next generation HTTP client for Python. Prior to 2.12.0, the HTTPX2 content decoders in src/httpx2/httpx2/_decoders.py fully inflate each gzip, deflate, br, or zstd network chunk before iter_bytes() or aiter_bytes() yields bounded pieces to the application. A 64 KiB compressed chunk can expand to approximately 64 MiB in one intermediate allocation, so an attacker-controlled or compromised server can cause severe memory pressure or out-of-memory process termination even when the application streams the response. This issue is fixed in version 2.12.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-84382)

Affected packages:

- `httpx2 < 2.12.0`

Patched in:

- `httpx2 2.12.0`

Source: https://osv.dev/vulnerability/GHSA-8xx6-hgc6-gc2m

## Vendor advisories

- **Red Hat VEX** · Important · affected: Lightspeed Core, Red Hat OpenShift AI (RHOAI) · no fix planned: Lightspeed Core, Red Hat OpenShift AI (RHOAI) · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84382.json)