---
id: CVE-2026-84379
title: HTTPX2 is a next generation HTTP client for Python
summary: >-
  HTTPX2 is a next generation HTTP client for Python. Prior to 2.11.0,
  FileField.render_headers() in src/httpx2/httpx2/_multipart.py directly
  interpolates attacker-controlled content_type values and custom headers from
  the files= three-ele…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-93
vendor: httpx2
product: httpx2
affected:
  - httpx2 < 2.11.0
patched:
  - httpx2 2.11.0
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-2026-84379'
references:
  - url: >-
      https://github.com/pydantic/httpx2/commit/de96d810ee4e309d118982fe7084a46a2bcd600d
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/pull/1142'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/releases/tag/v2.11.0'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/security/advisories/GHSA-h4x7-gw46-3wm6'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/security/advisories/GHSA-h4x7-gw46-3wm6'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84379'
  - url: 'https://github.com/pydantic/httpx2'
  - url: 'https://github.com/advisories/GHSA-h4x7-gw46-3wm6'
  - url: 'https://pypi.org/project/httpx2'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84379.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-84379'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2527696'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-84379'
tags:
  - nvd
  - osv
  - pip
  - ghsa
  - csaf
  - vex
  - red-hat
epss: 0.00448
epssPercentile: 0.36309
aliases:
  - GHSA-h4x7-gw46-3wm6
  - PYSEC-2026-3848
ecosystem: pip
ingestedAt: '2026-09-08T21:11:12.322Z'
---

## Overview

HTTPX2 is a next generation HTTP client for Python. Prior to 2.11.0, FileField.render_headers() in src/httpx2/httpx2/_multipart.py directly interpolates attacker-controlled content_type values and custom headers from the files= three-element (filename, content, content_type) tuple and the files= four-element (filename, content, content_type, headers) tuple into multipart/form-data part headers without validating header names or values. CR or LF characters can terminate a part header, inject additional part headers, or end the part header block early, allowing a downstream multipart parser to treat attacker-supplied lines as genuine headers and potentially alter part semantics or bypass header-based checks. This issue is fixed in version 2.11.0.

## Remediation

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

## Package advisory (CVE-2026-84379)

Affected packages:

- `httpx2 < 2.11.0`

Patched in:

- `httpx2 2.11.0`

Source: https://osv.dev/vulnerability/GHSA-h4x7-gw46-3wm6

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Lightspeed Core, Red Hat OpenShift AI (RHOAI) · no fix planned: Lightspeed Core, Red Hat OpenShift AI (RHOAI) · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84379.json)