CVE-2026-70482
Received Received - Intake

Open WebUI OAuth Token Exchange Session Hijacking

Publication date: 2026-08-04

Last updated on: 2026-08-04

Assigner: GitHub, Inc.

Description
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.

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Meta Information

Published
2026-08-04
Last Modified
2026-08-04
Generated
2026-08-05
AI Q&A
2026-08-04
EPSS Evaluated
N/A
NVD
CVE-2026-70482
EUVD
EUVD-2026-52887

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
open_webui open_webui From 0.8.0 (inc) to 0.11.0 (inc)
open_webui open_webui 0.11.0
open_webui open_webui to 0.11.0 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-287 When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

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Executive Summary

This vulnerability affects Open WebUI versions 0.8.0 to 0.11.0 when ENABLE_OAUTH_TOKEN_EXCHANGE is set to True. The /oauth/{provider}/token/exchange endpoint accepts any valid provider access token without verifying which OAuth client issued it. Attackers can exchange tokens minted for any client registered with the same provider to gain Open WebUI access as the token's user.

Detection Guidance

Check Open WebUI version with: curl -s http://localhost:8080/version | grep version. If version is between 0.8.0 and 0.11.0, the system is vulnerable. Inspect OAuth token exchange logs for unauthorized token exchanges or unusual client IDs.

Impact Analysis

If you use Open WebUI with OAuth token exchange enabled, an attacker could gain access to your account by exchanging a token they obtained for another client registered with your OAuth provider. This could lead to unauthorized access to your data, session takeover, or administrative privileges if you are an admin.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR's data protection principles and HIPAA's access controls. Organizations using Open WebUI may face compliance breaches if attackers access protected health information or personal data due to this flaw.

Mitigation Strategies

Upgrade Open WebUI to version 0.11.0 or later. If upgrading is not possible, disable ENABLE_OAUTH_TOKEN_EXCHANGE in configuration. Configure OAUTH_TOKEN_EXCHANGE_TRUSTED_CLIENT_IDS to restrict trusted clients. Review and revoke any suspicious sessions or tokens.

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