Path Traversal in Open-Webui
CVE-2026-28786
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.000
Affected products
- Open-Webui — versions < 0.8.6
- Openwebui Open Webui
Weakness classification (CWE)
References
- github.com/open-webui/open-webui/security/advisories/GHSA-vvxm-vxmr-624h (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-28786?
- CVE-2026-28786 is a medium-severity vulnerability in Open-Webui, classified under Path Traversal. CVSS score: 4.3/10. Published 2026-03-27.
- How severe is CVE-2026-28786?
- Medium severity. CVSS v3 base score is 4.3 out of 10.