Auth bypass in Open-Webui
CVE-2026-70482
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.0 until 0.11.0, when ENABLE_OAUTH_TOKEN_EXCHANGE=True, /oauth/{provider}/token/exchange accepts a raw provider access token and validates it by calling the provider userinfo endpoint without confirming which OAuth client the token was issued to. Anyone holding an access token minted for any client registered with the same provider could exchange it for an Open WebUI session as that token user, including applications the operator does not control and has never authorized. This issue is fixed in 0.11.0.
Vulnerability class: Broken Authentication
EPSS: 0.003 (27.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.
Affected products
- Open-webui — versions >= 0.8.0, < 0.11.0
- Openwebui Open_webui
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-70482?
- CVE-2026-70482 is a high-severity vulnerability in Open-Webui, classified under Improper Authentication. CVSS score: 8.1/10. Published 2026-08-04.
- How severe is CVE-2026-70482?
- High severity. CVSS v3 base score is 8.1 out of 10.