Authorization bypass in Open WebUI OAuth token exchange
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
Open WebUI from 0.11.1 before 0.11.4 has an authorization flaw (CWE-863) in its OAuth token exchange. It reads role claims only from the provider's userinfo response, ignoring roles in the ID token, and keeps the existing role when no roles claim is found. A user with a linked account whose provider role no longer meets the OAuth role policy can send a valid provider access token to the token exchange endpoint and get a session keeping the old role.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Open WebUI from 0.11.1 before 0.11.4 contains an authorization bypass in the OAuth token exchange endpoint, which reads role claims only from the provider's userinfo response and keeps the user's existing role when no roles claim is found, ignoring roles sent only in the ID token. Users with a linked account whose identity provider role no longer satisfies the OAuth role policy can send a valid provider access token to POST /api/v1/auths/oauth/{provider}/token/exchange to obtain a session retaining their previous role.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| open-webui | open-webui | 0.11.1 to before 0.11.4 | 0.11.4 | Patch available | CNA |
- open-webui Vendoropen-webui Affected 0.11.1 to before 0.11.4 Fixed in 0.11.4 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* | — | — | open-webui |
- cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions — — ·open-webui
Remediation
Upgrade Open WebUI to version 0.11.4, which fixes the flaw.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA open-webui (open-webui) Fixed in 0.11.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
open-webui 0.11.4
19 records Highest priority Priority HIGH 3 HIGH, 8 MEDIUM, 8 LOW
Other records, highest priority first
- TI-2026-71106 Stored cross-site scripting in Open WebUI via DOCX previewPriority HIGH 72
- TI-2026-71108 Session cookie disclosure in Open WebUI OAuth-mode connectionsPriority HIGH 68
- TI-2026-71104 Stored cross-site scripting in Open WebUI markdown linksPriority HIGH 67
Timeline
- 2026-10-12 Threatist record created from CVE-2026-109283
- 2026-10-12 Alias added: GHSA-wr8j-3xx4-g2v5
- 2026-10-13 CISA SSVC decision points changed
- 2026-10-13 Priority changed: LOW → MEDIUM
References
More open-webui vulnerabilities
- TI-2024-06216 Open WebUI Arbitrary File Upload + Path Traversal CVSS 3.1HIGH 8.8
- TI-2024-07467 Improper Authentication in open-webui/open-webui CVSS 3.1HIGH 8.2
- TI-2026-42359 Open WebUI: Cross-user code-interpreter and tool execution via unvalidated Socket.IO event-caller session_id CVSS 3.1CRITICAL 9.0
- TI-2026-40759 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation CVSS 4.0CRITICAL 9.0
- TI-2024-07431 Cross-site Scripting (XSS) in open-webui/open-webui CVSS 3.0CRITICAL 9.0
- TI-2026-60021 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin CVSS 3.1HIGH 8.7
Sources
- CVE-2026-109283 · CVE Program
- CVE-2026-109283 · NVD
- FIRST EPSS
- GHSA-wr8j-3xx4-g2v5 · GitHub Advisory Database · CC BY 4.0
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