---
id: CVE-2026-84381
title: HTTPX2 is a next generation HTTP client for Python
summary: >-
  HTTPX2 is a next generation HTTP client for Python. Prior to 2.10.0, httpcore2
  fails to start TLS in src/httpcore2/httpcore2/_sync/socks_proxy.py and
  src/httpcore2/httpcore2/_async/socks_proxy.py when the remote origin uses wss
  through a…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-319
vendor: httpcore2
product: httpcore2
affected:
  - httpcore2 < 2.10.0
  - 'httpx2 >= 2.6.0, < 2.10.0'
patched:
  - httpcore2 2.10.0
  - httpx2 2.10.0
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-2026-84381'
references:
  - url: >-
      https://github.com/pydantic/httpx2/commit/fb008dd700b761d955210d9692475c3e2f379453
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/pull/1104'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/releases/tag/v2.10.0'
    label: security-advisories@github.com
  - url: 'https://github.com/pydantic/httpx2/security/advisories/GHSA-7mj9-2mp8-4m2p'
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84381'
  - url: 'https://github.com/advisories/GHSA-7mj9-2mp8-4m2p'
  - url: 'https://github.com/pydantic/httpx2'
  - url: 'https://pypi.org/project/httpcore2'
  - url: 'https://pypi.org/project/httpx2'
tags:
  - nvd
  - ghsa
  - pip
  - osv
epss: 0.00115
epssPercentile: 0.01403
aliases:
  - GHSA-7mj9-2mp8-4m2p
  - PYSEC-2026-3844
  - PYSEC-2026-3845
ecosystem: pip
ingestedAt: '2026-09-05T20:44:35.395Z'
---

## Overview

HTTPX2 is a next generation HTTP client for Python. Prior to 2.10.0, httpcore2 fails to start TLS in src/httpcore2/httpcore2/_sync/socks_proxy.py and src/httpcore2/httpcore2/_async/socks_proxy.py when the remote origin uses wss through a SOCKS5 proxy because the TLS upgrade condition only recognizes https. HTTPX2 exposes the flaw through Client.websocket() and AsyncClient.websocket() from 2.6.0 through 2.9.1, so the opening handshake, query parameters, Authorization headers, cookies, and subsequent frames can cross the proxy path in plaintext without certificate verification. An attacker controlling or observing that path can read or modify traffic and impersonate the WebSocket server. This issue is fixed in httpcore2 2.10.0 and HTTPX2 2.10.0.

## Remediation

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

## Package advisory (CVE-2026-84381)

Affected packages:

- `httpcore2 < 2.10.0`
- `httpx2 >= 2.6.0, < 2.10.0`

Patched in:

- `httpcore2 2.10.0`
- `httpx2 2.10.0`

Source: https://github.com/advisories/GHSA-7mj9-2mp8-4m2p