High, CVSS 8.1PyPIAmendedPublished
HTTPX2: Secure WebSocket traffic sent without TLS through SOCKS proxies
CVE-2026-84381 · GHSA-7mj9-2mp8-4m2p
- Affected
- PyPI httpcore2 < 2.10.0
- Fixed in
- 2.10.0· Vendor fix available
- Issue
- httpcore2 does not start TLS for wss:// connections routed through a SOCKS5 proxy. The WebSocket opening handshake and all subsequent frames are sent in plaintext through the proxy path, despite the caller selecting the secure wss scheme. The transport flaw affects httpcore2 releases before 2.10.0. HTTPX2 exposed this behavior through its public Client.websocket() and AsyncClient.websocket() APIs from 2.6.0 through 2.9.1. Details The synchronous and asynchronous SOCKS5 connection implementations upgrade the established proxy tunnel to TLS only when the remote origin scheme is https. The equivalent check does not include wss. After the SOCKS5 handshake succeeds, the raw stream is therefore passed directly to the HTTP/1.1 connection, which writes the WebSocket upgrade request without first performing a TLS handshake or verifying the destination certificate. For example, an application using HTTPX2 2.6.0 through 2.9.1 may open an authenticated WebSocket through a SOCKS proxy: On…
Recommended action: Upgrade to 2.10.0 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.