Auth bypass in Open-Webui
CVE-2026-87997
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, POST /api/chat/completions and POST /api/v1/chat/completions in backend/open_webui/main.py copied a client-supplied folder_id into a new chat without applying the folder write-access check used by the dedicated chat routes. An authenticated user who knew a shared folder identifier could inject an attacker-controlled chat into a folder where the user had read-only or no write access, causing the entry to appear to authorized folder readers. This issue is fixed in version 0.11.1.
Vulnerability class: IDOR (Insecure Direct Object Reference)
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:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (30.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.0% 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 >= 0.10.0, < 0.11.1
- Openwebui Open Webui
Weakness classification (CWE)
References
- github.com/open-webui/open-webui/security/advisories/GHSA-3pf7-q2g3-wj28 (Exploit, Vendor Advisory)
- github.com/open-webui/open-webui/pull/28366 (Patch, Issue Tracking)
- github.com/open-webui/open-webui/commit/d9e23b90c100d19b00270aea3cde0501d2354a6c (Patch)
- github.com/open-webui/open-webui/releases/tag/v0.11.1 (Release Notes)
Frequently asked questions
- What is CVE-2026-87997?
- CVE-2026-87997 is a medium-severity vulnerability in Open-Webui, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2026-09-09.
- How severe is CVE-2026-87997?
- Medium severity. CVSS v3 base score is 4.3 out of 10.