Open WebUI SSE Flaw Allows Malicious Model Server Takeover
⚠ Security researchers at Cato Networks disclosed CVE-2025-64496, a vulnerability in Open WebUI that lets external model servers inject JavaScript via Server-Sent Events (SSE) when the Direct Connections feature is enabled. An attacker controlling a malicious model endpoint can exfiltrate JSON Web Tokens (JWTs) from the browser, enabling account takeover and access to documents, chats, and embedded API keys. If the compromised account has Workspace Tools privileges, the session token can be used to execute authenticated Python code on the backend, leading to remote code execution. The flaw affects versions up to 0.6.34 and is fixed in 0.6.35; organizations are urged to update and implement HttpOnly cookies, strict CSPs, and ban dynamic code evaluation.
