Open WebUI: Chat completion API allows tool restrictions to be bypassed
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-862.
Summary
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.6, there is a vulnerability in chat completion API, which allows attackers to bypass tool restrictions, potentially enabling unauthorized actions or access. In the chat_completion API, the parameters tool_ids and tool_servers are supplied by the user. These parameters are used to create a tools_dict by the middleware. This is then used by get_tool_by_id to retrieve the appropriate tool. However, there is no checks in that ensures the user that uses the API has permission to use the tool, meaning that a user can invoke any server tool by supplying the correct tool_id or tool_servers parameters via the chat completion API. Moreover, the authentication token stored in the server would be used when invoking the tool, so the tool will be invoked with the server privilege. This vulnerability is fixed in 0.8.6.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| open-webui | open-webui | before 0.8.6 | 0.8.6 | Patch available | CNA |
| — | open-webui (PyPI) | before 0.8.6 | 0.8.6 | Patch available | GHSA-4pcg-253r-rf9w |
- open-webui Vendoropen-webui Affected before 0.8.6 Fixed in 0.8.6 Patch available CNA
- open-webui (PyPI) Vendor— Affected before 0.8.6 Fixed in 0.8.6 Patch available GHSA-4pcg-253r-rf9w
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* | before 0.8.6 | Vulnerable | open-webui |
- cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions before 0.8.6 Vulnerable ·open-webui
Remediation
- Fix · CNA open-webui (open-webui) Fixed in 0.8.6
- Fix · GHSA-4pcg-253r-rf9w open-webui (PyPI) Fixed in 0.8.6 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45350
- 2026-10-03 Alias added: GHSA-4pcg-253r-rf9w
References
More open-webui Open Webui vulnerabilities
- TI-2024-06216 Open WebUI Arbitrary File Upload + Path Traversal CVSS 3.1HIGH 8.8
- TI-2024-07467 Improper Authentication in open-webui/open-webui CVSS 3.1HIGH 8.2
- TI-2026-42359 Open WebUI: Cross-user code-interpreter and tool execution via unvalidated Socket.IO event-caller session_id CVSS 3.1CRITICAL 9.0
- TI-2026-40759 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation CVSS 4.0CRITICAL 9.0
- TI-2024-07431 Cross-site Scripting (XSS) in open-webui/open-webui CVSS 3.0CRITICAL 9.0
- TI-2026-60021 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin CVSS 3.1HIGH 8.7
Sources
- CVE-2026-45350 · CVE Program
- CVE-2026-45350 · NVD
- FIRST EPSS
- GHSA-4pcg-253r-rf9w · GitHub Advisory Database · CC BY 4.0
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