CVE-2026-84381 HTTPX2: Secure WebSocket traffic sent without TLS through SOCKS proxies
HTTPX2 sends WebSocket traffic over SOCKS proxies without TLS, allowing attackers to read or modify sensitive data and impersonate servers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-84381?
CVE-2026-84381 is a high-severity vulnerability in pydantic httpcore2, published on 2 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-319
Which versions are affected by CVE-2026-84381?
6 open source packages ship an affected version, including httpcore2 and httpx2.
| Package | Affected | Fixed in |
|---|---|---|
httpcore2 PyPI | All versions | 2.10.0 |
httpcore2 PyPI | All versions | 2.10.0 |
httpcore2 PyPI | All versions | 2.10.0 |
httpx2 PyPI | From 2.6.0 | 2.10.0 |
httpx2 PyPI | From 2.6.0 | 2.10.0 |
httpx2 PyPI | From 2.6.0 | 2.10.0 |
How do I fix CVE-2026-84381?
Upgrade httpcore2 to 2.10.0 or later.
Is CVE-2026-84381 being exploited?
There is no known exploitation of CVE-2026-84381 in the wild and no public exploit code.
Sources
Also known as ECHO-2af1-2f46-154f, GHSA-7mj9-2mp8-4m2p, MINI-794m-j5jh-44gg, PYSEC-2026-3844, PYSEC-2026-3845, ROOT-APP-PYPI-CVE-2026-84381 and 1 more.