CVE-2026-34222 — open-webui
HIGHCVE-2026-34222 is a high-severity (CVSS 7.7) CWE-285 vulnerability in open-webui. A fix is available for open-webui — see the affected versions and patch details below.
Open WebUI has Broken Access Control in Tool Valves
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-34222.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-34222 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
open-webuiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Broken Access Control in Tool Valves
Open WebUI supports function calling through "Tools". Function calling allows an LLM to reliably connect to external tools and interact with external APIs. Exemplary use-cases include connecting to an internal knowledge base, retrieving emails from an exchange server, or retrieving order data from a shop backend.
These interactions often require the LLM to authenticate against backend services using API keys specifically created for a technical (Open WebUI) user.
To simplify configuration and secret handling, Open WebUI implements "Valves" and "UserValves" that allow users and administrators to input dynamic details like API keys or configuration options.
Valves have the following distinction:
- Valves: Configurable by admins only.
- UserValves: Configurable by any user.
The Tool Valves endpoint does not properly restrict read access to the valve. This allows a low privileged user to access all data contained within the valve. In the worst case, this gives a low privileged "Member" user access to sensitive Tool data, such as API keys for third-party systems.
Details
1) Broken Access Control in Tool Valves
The following steps can be performed to reproduce the vulnerability.
1. An administrator creates an Open WebUI Tool with a configured Valve.
<img width="1038" height="597" alt="image" src="https://github.com/user-attachments/assets/f79bdde9-18fa-49e4-a6c3-5077731f0815" />2. The administrator configures the API key within the Tool Valve.
<img width="1039" height="446" alt="image" src="https://github.com/user-attachments/assets/d88d06b9-fc21-45e5-8142-d9f874601f87" />3. A user with at least "Member" privileges logs into Open WebUI.
The following screenshot shows the user overview of the test instance:
<img width="908" height="354" alt="image" src="https://github.com/user-attachments/assets/40025151-418d-4912-8400-1e1a6e5cd4e4" />The following screenshot illustrates that the "lowpriv" user doesn't have access to the tool:
<img width="815" height="433" alt="image" src="https://github.com/user-attachments/assets/ec06b07f-9735-4728-9dce-d97d721051b8" />4. The "lowpriv" user uses their Authorization token to retrieve the API key from the Tool Valve.
In order to do so, the attacker needs to know the Tool ID. However, as this ID is always the same for imported tools, and the tool IDs are concatenated from the tool name, guessing tool IDs is trivial.
<img width="754" height="208" alt="image" src="https://github.com/user-attachments/assets/61c80cac-25c8-4730-8156-90869801389f" />As seen in the following code snippet, the vulnerability is present because the Tool Valves route does not check if the requesting user has administrative permissions (Line 515).
Source: backend/open_webui/routers/tools.py L513–L531
PoC
You can find the detailed PoC steps in the Details section.
To execute the exploit:
- Login as a verified user and copy the authorization token.
- Access the configured valve of any existing tool with the following request (please mind the placeholders):
GET /api/v1/tools/id/<tool_id>/valves HTTP/1.1
Host: <your_test_host>
Authorization: Bearer <authorization_token_from_step_1>
Impact
This information disclosure vulnerability allows low privileged users to access sensitive values stored in Tool Valves. Anyone using Open WebUI Tools with a configured Valve is affected. In the worst case, exploitation allows an attacker to access third-party systems within the context of the configured Open WebUI technical user.
Additional Remarks
Additional remarks regarding the CVSS Vector String:
| Component | Value | Rationale |
|---|---|---|
| AC | L | Due to the requirement of a "Member" account |
| C | H | Sensitive data, such as API Keys for backend systems, is disclosed |
| S | C | Exploitation of this vulnerability grants access to third-party systems |
AI report transparency: AI was used for refinement of this advisory text.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | open-webui | all versions | 0.8.11pip install --upgrade 'open-webui==0.8.11' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for open-webui, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update open-webui to 0.8.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34222 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-34222 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-34222. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-34222 in your dependencies?
O3 Security finds CVE-2026-34222 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.