CVE-2026-88005
Received Received - Intake

OAuth Token Exchange Session Bypass in Open WebUI

Publication date: 2026-09-10

Last updated on: 2026-09-10

Assigner: GitHub, Inc.

Description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.0 until 0.9.0, Open WebUI's OAuth token exchange endpoint issues a session for a provider access token without applying the email domain allowlist that the normal OAuth login callback enforces. An account whose email domain the login callback would refuse could still obtain a working session through this endpoint. This issue is fixed in version 0.9.0.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-10
Last Modified
2026-09-10
Generated
2026-09-10
AI Q&A
2026-09-10
EPSS Evaluated
N/A
NVD
CVE-2026-88005
EUVD
EUVD-2026-75540

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
open_webui open_webui to 0.9.0 (inc)
open_webui open_webui From 0.8.0 (inc) to 0.9.0 (exc)
open_webui open_webui 0.9.0

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-863 The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in Open WebUI (versions 0.8.0 to 0.9.0) involves the OAuth token exchange endpoint not enforcing the email domain allowlist that the normal OAuth login callback applies. This allows users with tokens from non-allowed domains to bypass domain restrictions and gain unauthorized access.

Detection Guidance

Check Open WebUI version with: curl -s https://your-openwebui-instance.com/api/version | grep version. If version is between 0.8.0 and 0.9.0, the system is vulnerable. Review OAuth logs for token exchange attempts from non-allowed domains.

Impact Analysis

If you are an administrator using Open WebUI with domain allowlisting, unauthorized users from non-allowed domains could gain access to your system through the token exchange feature. This could lead to data breaches or unauthorized use of resources.

Compliance Impact

This vulnerability could violate compliance requirements that mandate strict access controls and domain restrictions, such as GDPR's data protection principles or HIPAA's access controls. Unauthorized access risks non-compliance with these regulations.

Mitigation Strategies

Upgrade Open WebUI to version 0.9.0 or later immediately. Verify domain allowlist enforcement in OAuth settings. Disable token exchange if not required. Monitor for unauthorized access attempts.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-88005. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart