---
id: "CVE-2026-107685"
kind: "vulnerability"
aliases: ["CVE-2026-107685"]
title: "req_llm: WebSocket client skips TLS checks, exposing OpenAI bearer tokens"
severity: "critical"
cvss: 9.1
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["ai-tooling", "elixir", "openai", "req-llm", "websocket"]
not_affected_if: ["http-streaming-only", "no-openai-websocket-use"]
published_at: "2026-10-23T12:18:06+00:00"
first_seen_at: "2026-10-23T21:57:32+00:00"
updated_at: "2026-10-23T22:31:24+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-107685", "first_seen_at": "2026-10-23T21:57:32+00:00"}]
---

# req_llm: WebSocket client skips TLS checks, exposing OpenAI bearer tokens

The Elixir req_llm library's WebSocket streaming client connects to OpenAI without verifying the server's TLS certificate, and it blocks callers from turning verification on. An attacker on the network path can read and change OpenAI WebSocket sessions and capture the API key or OAuth token sent in the authorization header.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Check the req_llm version in mix.lock: affected if it is from 1.9.0 before 1.29.0 and the app uses the OpenAI Responses, Realtime, or Codex WebSocket paths.

## Fix

Upgrade req_llm to 1.29.0 or later, then rotate any OpenAI API keys or OAuth tokens that were sent over these WebSocket paths.

## Timeline

- 2026-10-23T21:57:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-107685

## From the sources

Improper Certificate Validation vulnerability in the WebSocket streaming client in agentjido req_llm allows an on-path attacker to read and modify OpenAI WebSocket sessions, including the authorization bearer token, via a TLS certificate the client does not trust. ReqLLM.Streaming.WebSocketSession.Client.start/3 in lib/req_llm/streaming/web_socket_session/client.ex starts WebSockex without TLS options, and WebSockex defaults to insecure: true, which connects with verify: :verify_none. The option allowlist also drops any caller-supplied cacerts or ssl_options, so an application cannot turn verification on.

The OpenAI Responses, Realtime, and Codex WebSocket paths reach this client and send the API key or OAuth access token in the authorization header. HTTP streaming through Finch and the HTTP/2 duplex session through Mint verify certificates and are not affected.

This issue affects req_llm: from 1.9.0 before 1.29.0.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_