---
id: "GHSA-w466-2wfc-8g58"
kind: "vulnerability"
aliases: ["GHSA-w466-2wfc-8g58"]
title: "Open WebUI has vulnerable dependency on starlette via fastapi"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "open-webui", "fixed": ["0.5.8"], "affected": "< 0.5.8", "ecosystem": "pypi"}]
ecosystems: ["pypi"]
tags: ["ai-tooling", "cwe-400", "fastapi", "open-webui", "python", "self-hosted", "starlette"]
not_affected_if: ["default-config"]
published_at: "2025-03-20T12:32:44+00:00"
first_seen_at: "2026-10-26T15:12:52+00:00"
updated_at: "2026-10-26T15:13:42+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-w466-2wfc-8g58", "first_seen_at": "2026-10-26T15:12:52+00:00"}]
---

# Open WebUI has vulnerable dependency on starlette via fastapi

Open WebUI pulls in a vulnerable version of the starlette package through its fastapi dependency. An attacker can send requests that consume unbounded memory and crash the service (denial of service).

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- pypi:open-webui affected < 0.5.8 fixed 0.5.8

## How to check

- Check the installed open-webui version with `pip show open-webui`, and treat anything below `0.5.8` as affected.
- Check the resolved starlette version with `pip show starlette`; versions `<=0.49` are susceptible.
- Check the resolved fastapi version with `pip show fastapi`; versions below `0.115.3` pull in the vulnerable starlette.

## Fix

- Upgrade open-webui to `0.5.8` or later.
- Upgrade fastapi to `0.115.3` or later so that starlette is no longer vulnerable.

## Timeline

- 2026-10-26T15:12:52+00:00 ghsa https://github.com/advisories/GHSA-w466-2wfc-8g58

## From the sources

In version 0.3.32 of open-webui, the application uses a vulnerable version of the starlette package through its dependency on fastapi. The starlette package versions <=0.49 are susceptible to uncontrolled resource consumption, which can be exploited to cause a denial of service through memory exhaustion. This issue is addressed in fastapi version 0.115.3.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_