CVE-2026-28786 Open WebUI vulnerable to Path Traversal in `POST /api/v1/audio/transcriptions`
Authenticated users can trigger path traversal errors in Open WebUI, leaking server directory paths in error messages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-28786?
CVE-2026-28786 is a medium-severity path traversal vulnerability in Openwebui Open Webui, published on 26 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, an unsanitized filename field in the speech-to-text transcription endpoint allows any authenticated non-admin user to trigger a `FileNotFoundError` whose message — including the server's absolute `DATA_DIR` path — is returned verbatim in the HTTP 400 response body, confirming information disclosure on all default deployments. Version 0.8.6 patches the issue.
Which versions are affected by CVE-2026-28786?
3 open source packages ship an affected version, including open-webui. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
open-webui PyPI | All versions | 0.8.6 |
open-webui PyPI | All versions | 0.8.6 |
open-webui PyPI | All versions | 0.8.6 |
Products include Openwebui Open Webui.
How do I fix CVE-2026-28786?
Upgrade open-webui to 0.8.6 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-28786 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28786 exists.
Other vulnerabilities in Openwebui Open Webui
- CVE-2026-44551 Open WebUI: LDAP Empty Password Authentication Bypass
- CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
- CVE-2024-8017 Cross-site Scripting (XSS) in open-webui/open-webui
- CVE-2026-45672 Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed
- CVE-2026-87995 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin
Sources
Also known as GHSA-vvxm-vxmr-624h, PYSEC-2026-2764.