Open WebUI: shared-chat branch ignores access_type, allowing unauthorized file deletion
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-639.
Summary
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, any authenticated user can permanently delete files owned by other users via DELETE /api/v1/files/{id} when the target file is referenced in any shared chat. The has_access_to_file() authorization gate unconditionally grants access through its shared-chat branch. It checks neither the requesting user's identity nor the type of operation being performed. File UUIDs (which would otherwise be impractical to guess) are disclosed to any user with read access to a knowledge base via GET /api/v1/knowledge/{id}/files. This vulnerability is fixed in 0.9.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
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 0.9.0 | 0.9.0 | Patch available | CNA |
| — | open-webui (PyPI) | before 0.9.0 | 0.9.0 | Patch available | GHSA-26g9-27vm-x3q8 |
- open-webui Vendoropen-webui Affected before 0.9.0 Fixed in 0.9.0 Patch available CNA
- open-webui (PyPI) Vendor— Affected before 0.9.0 Fixed in 0.9.0 Patch available GHSA-26g9-27vm-x3q8
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* | before 0.9.0 | Vulnerable | open-webui |
- cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions before 0.9.0 Vulnerable ·open-webui
Remediation
- Fix · CNA open-webui (open-webui) Fixed in 0.9.0
- Fix · GHSA-26g9-27vm-x3q8 open-webui (PyPI) Fixed in 0.9.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45671
- 2026-10-03 Alias added: GHSA-26g9-27vm-x3q8
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-2026-45671 · CVE Program
- CVE-2026-45671 · NVD
- FIRST EPSS
- GHSA-26g9-27vm-x3q8 · GitHub Advisory Database · CC BY 4.0
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