GHSA-6wj5-5pgr-jwq8 Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability in api/chat/file

Not scored Published

Unauthenticated attackers can cause a Denial of Service in Open WebUI by uploading files with malformed multipart boundaries, rendering the application inaccessible.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is GHSA-6wj5-5pgr-jwq8?

GHSA-6wj5-5pgr-jwq8 is a denial of service vulnerability in open-webui, published on 20 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in open-webui/open-webui version 79778fa allows an attacker to cause a Denial of Service (DoS) by uploading a file with a malformed multipart boundary. By appending a large number of characters to the end of the multipart boundary, the server continuously processes each character, rendering the application inaccessible. This issue can prevent all users from accessing the application until the server recovers.

Which versions are affected by GHSA-6wj5-5pgr-jwq8?

2 open source packages ship an affected version, including open-webui.

PackageAffectedFixed in
open-webui PyPIAll versions0.4.7
open-webui PyPIAll versions0.4.7

How do I fix GHSA-6wj5-5pgr-jwq8?

Upgrade open-webui to 0.4.7 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is GHSA-6wj5-5pgr-jwq8 being exploited?

There is no known exploitation of GHSA-6wj5-5pgr-jwq8 in the wild and no public exploit code.

Sources

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