CVE-2024-7999: Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability
Summary
CVE-2024-7999: Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability in api/chat/file. Affects open-webui versions < 0.4.7. Fixed in 0.4.7. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
Open WebUI is an open-source web interface designed for chat applications, allowing users to upload files and communicate seamlessly. It is built on Python and is widely used due to its user-friendly interface and robust features. However, it has been identified to have a critical vulnerability that can lead to a Denial of Service (DoS) attack, affecting its availability and performance.
Vulnerability Detail
A vulnerability in open-webui version 79778fa allows an attacker to exploit the file upload functionality by sending a malformed multipart boundary. This malformed boundary can be crafted by appending a large number of characters, causing the server to process each character continuously. As a result, the application becomes inaccessible to all users until the server recovers, leading to significant downtime and disruption.
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
0.4.7
This is the first release that contains the fix.
pip install --upgrade "open-webui==0.4.7"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, you can implement input validation on the server-side to limit the size and format of the multipart boundary. This can help mitigate the risk of the DoS attack until the package is updated. Example code for input validation could look like this:
if len(multipart_boundary) > MAX_LENGTH: raise ValueError('Multipart boundary too long')
Conclusion
The CVE-2024-7999 vulnerability in the open-webui package poses a significant risk of Denial of Service attacks. It is crucial to update to the patched version 0.4.7 to mitigate this risk. Additionally, implementing input validation can serve as a temporary workaround until the update is applied.
See every vulnerability recorded for open-webui →
FAQ
The impact of this vulnerability is a Denial of Service (DoS), which can render the application inaccessible to users.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The CVSS score for this vulnerability is 7.5, indicating a high severity level.
Yes, a patch is available in version 0.4.7 of the open-webui package. It is recommended to update to this version.
If you cannot update the package immediately, implement server-side input validation to limit the multipart boundary size as a temporary measure.
References
Related vulnerabilities
Recent vulnerabilities recorded for open-webui.
