CVE-2025-64496

Open WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE Events

VULNERABILITY TYPE: Code Injection via Untrusted External Data Source

WHO IS IMPACTED:

• All users who enable Direct Connections feature
• Organizations allowing external model endpoints
• Users adding local models (Ollama, LM Studio, custom APIs)
• Development and testing environments
• Direct Connections is admin-controllable but affects all users once enabled
• Common in organizations using "bring your own model" policies
• Social engineering success rate is high ("Try my free GPT-4")
• Feature is designed for external connections, making attacks plausible

ATTACK SCENARIOS:

Scenario 1: Corporate Espionage

• Attacker targets company using Open WebUI
• Posts "free GPT-4 alternative" on Reddit/HackerNews
• Company employees add the malicious model
• Multiple tokens stolen including admin
• Full access to company's AI conversations and data

Scenario 2: Supply Chain Attack

• MSP hosts Open WebUI for 50 clients
• MSP employee tests malicious model
• Admin token stolen
• Attacker gains access to all 50 client instances

Scenario 3: Insider Threat Amplification

• Disgruntled employee with user account
• Deploys malicious model
• Shares in company Slack: "Cool new model!"
• Admin tests it, token stolen
• Employee escalates to admin privileges

Please note that once this vulnerability is fixed, we are going to release a blog. I work as a security researcher for Cato Networks.

CVE-2025-64496 has a CVSS score of 7.3 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.6.35); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-64496? CVE-2025-64496 is a high-severity security vulnerability in open-webui (npm), affecting versions <= 0.6.34. It is fixed in 0.6.35.
2. How severe is CVE-2025-64496? CVE-2025-64496 has a CVSS score of 7.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of open-webui are affected by CVE-2025-64496? open-webui (npm) versions <= 0.6.34 is affected.
4. Is there a fix for CVE-2025-64496? Yes. CVE-2025-64496 is fixed in 0.6.35. Upgrade to this version or later.
5. Is CVE-2025-64496 exploitable, and should I be worried? Whether CVE-2025-64496 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-64496 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-64496?
   • Upgrade open-webui to 0.6.35 or later
   • Upgrade open-webui to 0.6.35 or later