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.
History

Thu, 03 Sep 2026 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Pydantic
Pydantic httpcore2
Pydantic httpx2
Vendors & Products Pydantic
Pydantic httpcore2
Pydantic httpx2

Thu, 03 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Wed, 02 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
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.
Title HTTPX2: Secure WebSocket traffic sent without TLS through SOCKS proxies
Weaknesses CWE-319
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-02T18:01:31.126Z

Updated: 2026-09-02T18:01:31.126Z

Reserved: 2026-09-01T16:27:58.130Z

Link: CVE-2026-84381

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-02T19:18:08.217

Modified: 2026-09-02T19:18:08.217

Link: CVE-2026-84381

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-02T18:01:31Z

Links: CVE-2026-84381 - Bugzilla