Open WebUI: Authenticated users can target arbitrary configured Ollama backends via unguarded url_idx path parameter
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-863.
Summary
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, several direct, index-addressed Ollama proxy routes accept a caller-supplied url_idx path parameter and use it as a raw index into the admin-configured OLLAMA_BASE_URLS list. Access control on these routes validates only whether the user may use the requested model, never which backend the request is routed to. Any authenticated user can append an arbitrary url_idx to force their request onto an Ollama backend they were never authorized to reach, including internal, higher-privilege, or explicitly admin-disabled backends. This vulnerability is fixed in 0.9.6.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- 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 0.9.6 | 0.9.6 | Patch available | CNA |
| — | open-webui (PyPI) | before 0.9.6 | 0.9.6 | Patch available | GHSA-9rpj-v7hf-vv2w |
- open-webui Vendoropen-webui Affected before 0.9.6 Fixed in 0.9.6 Patch available CNA
- open-webui (PyPI) Vendor— Affected before 0.9.6 Fixed in 0.9.6 Patch available GHSA-9rpj-v7hf-vv2w
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* | before 0.9.6 | Vulnerable | open-webui |
- cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions before 0.9.6 Vulnerable ·open-webui
Remediation
- Fix · CNA open-webui (open-webui) Fixed in 0.9.6
- Fix · GHSA-9rpj-v7hf-vv2w open-webui (PyPI) Fixed in 0.9.6 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54021
- 2026-10-03 Alias added: GHSA-9rpj-v7hf-vv2w
References
Advisory 3
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-2026-54021 · CVE Program
- CVE-2026-54021 · NVD
- FIRST EPSS
- GHSA-9rpj-v7hf-vv2w · GitHub Advisory Database · CC BY 4.0
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