CORS Misconfiguration and Session Validation Flaw in Open WebUI
Summary
GHSA-6xcp-7mpr-m7wm: Open WebUI has a CORS misconfiguration and session validation issue. Affects open-webui versions < 0.3.33. Fixed in 0.3.33. How to fix ↓
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Background
Open WebUI is an open-source web application designed to provide a user-friendly interface for various backend functionalities. It allows users to manage and interact with different services through a centralized platform. However, the application has been found to have critical security vulnerabilities that could lead to unauthorized access and remote code execution.
Vulnerability Detail
The vulnerability stems from a CORS misconfiguration and a failure to invalidate session cookies upon logout. The CORS misconfiguration allows arbitrary websites to make authenticated cross-site requests to the Open WebUI, enabling attackers to execute arbitrary code if they gain access to an admin account. Additionally, the failure to invalidate session cookies means that even after a user logs out, the same session cookies can be reused, allowing attackers to exploit this flaw without needing the user to be logged in. This combination of issues significantly increases the risk of remote code execution and unauthorized access.
How To Fix
Latest published version: 0.12.3 as of 22 Oct 2026
pip install --upgrade "open-webui==0.12.3"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
0.3.33
This is the first release that contains the fix.
pip install --upgrade "open-webui==0.3.33"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, you can restrict access to the Open WebUI by implementing network-level controls such as firewalls or VPNs to limit exposure until the vulnerabilities are patched. Additionally, avoid using the application in environments where untrusted users can access it.
Conclusion
The Open WebUI has critical vulnerabilities due to CORS misconfiguration and session validation issues, which can lead to remote code execution and unauthorized access. It is essential to update to the latest version to mitigate these risks and ensure the security of the application.
See every vulnerability recorded for open-webui →
FAQ
The CVSS score of this vulnerability is 8.3, indicating a high severity level.
You can use Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected without needing to sign up.
The potential impacts include unauthorized remote code execution, data breaches, and complete compromise of the application running in a Docker container.
Yes, a patch is available in version 0.3.33 of Open WebUI. It is recommended to update to this version to mitigate the vulnerabilities.
If you cannot update the package immediately, implement network-level controls to restrict access and monitor for any suspicious activity until you can apply the patch.
References
Related vulnerabilities
Recent vulnerabilities recorded for open-webui.
