CVE-2026-107685

Name of the Vulnerable Software and Affected Versions req llm versions 1.9.0 through 1.28.0

Description Improper certificate validation in the WebSocket streaming client allows an on-path attacker to read and modify OpenAI WebSocket sessions, including the authorization bearer token. The function ReqLLM.Streaming.WebSocketSession.Client.start/3 in lib/req llm/streaming/web socket session/client.ex initiates WebSockex without TLS options. Because WebSockex defaults to insecure: true, it connects using verify: :verify none, which accepts any certificate. Additionally, the option allowlist discards caller-supplied cacerts or ssl options, preventing applications from enabling verification. This affects the OpenAI Responses, Realtime, and Codex WebSocket paths, which transmit API keys or OAuth access tokens in the authorization header.

Recommendations Update req llm to version 1.29.0 or later. As a temporary workaround, keep the openai stream transport provider option at its default :sse for OpenAI and OpenAI Codex providers and avoid calling ReqLLM.Providers.OpenAI.WebSocket.start responses session/2 directly. Avoid using ReqLLM.OpenAI.Realtime.connect/2 on affected versions as it has no HTTP alternative.