Auth bypass in Open-Webui
CVE-2026-70487
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, inline direct model metadata accepted client-supplied knowledge attachments without filtering them against the caller's read access. Any authenticated user who knew another user's file id could have the builtin knowledge tools return indexed chunks from that file, causing a read-only cross-user confidentiality loss while leaving knowledge-base permissions and saved workspace model validation unaffected. This issue is fixed in 0.11.0.
Vulnerability class: Broken Access Control
EPSS: 0.003 (16.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Open-webui — versions >= 0.8.8, < 0.11.0
- Openwebui Open_webui
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-70487?
- CVE-2026-70487 is a medium-severity vulnerability in Open-Webui, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-08-04.
- How severe is CVE-2026-70487?
- Medium severity. CVSS v3 base score is 5.3 out of 10.