{"id":"GHSA-w466-2wfc-8g58","kind":"vulnerability","aliases":["GHSA-w466-2wfc-8g58"],"related":[],"title":"Open WebUI has vulnerable dependency on starlette via fastapi","description":"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.","summary":"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).","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"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"],"how_to_check":"- Check the installed open-webui version with `pip show open-webui`, and treat anything below `0.5.8` as affected.\n- Check the resolved starlette version with `pip show starlette`; versions `<=0.49` are susceptible.\n- 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.\n- Upgrade fastapi to `0.115.3` or later so that starlette is no longer vulnerable.","status":"open","published_at":"2025-03-20T12:32:44+00:00","first_seen_at":"2026-10-26T15:12:52+00:00","triaged_at":"2026-10-26T15:13:42+00:00","updated_at":"2026-10-26T15:13:42+00:00","category":"ai-tooling","confidence":0.7,"triage":{"at":"2026-10-26T15:13:42Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade open-webui to `0.5.8` or later.\n- Upgrade fastapi to `0.115.3` or later so that starlette is no longer vulnerable.","reach":"internet","title":"Open WebUI: vulnerable starlette via fastapi lets requests exhaust memory","impact":"low","summary":"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).","category":"ai-tooling","nicknames":[],"who_cares":["open-webui","self-hosted","python","fastapi","starlette"],"confidence":0.7,"needs_auth":"unknown","worst_case":"Service becomes unavailable through memory exhaustion","analyst_note":"","how_to_check":"- Check the installed open-webui version with `pip show open-webui`, and treat anything below `0.5.8` as affected.\n- Check the resolved starlette version with `pip show starlette`; versions `<=0.49` are susceptible.\n- Check the resolved fastapi version with `pip show fastapi`; versions below `0.115.3` pull in the vulnerable starlette.","needs_analyst":false,"not_affected_if":["default-config"],"who_is_affected":"Any deployment of Open WebUI older than 0.5.8 that resolves a vulnerable starlette through fastapi is exposed. The exposure depends on the service being reachable by requests, so internet-facing or shared-network instances are the ones to check first. Instances already on 0.5.8 or later with a current fastapi can skip it.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.00063,"input_tokens":3363,"output_tokens":588,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-400':27B '0.115.3':121C '0.3.32':70C '0.49':94C '2wfc':13A,18A '8g58':14A,19A 'address':117C 'ai':24B 'ai-tool':23B 'applic':76C 'attack':53B 'caus':106C 'consum':58B 'consumpt':100C 'crash':62B 'cwe':26B 'denial':65B,108C 'depend':5A,51B,87C 'exhaust':113C 'exploit':104C 'fastapi':9A,28B,50B,89C,119C 'ghsa':11A,16A 'ghsa-w466-2wfc-8g58':10A,15A 'host':35B 'issu':115C 'memori':60B,112C 'open':1A,21A,30B,37B,73C 'open-webui':20A,29B,72C 'packag':47B,84C,92C 'pull':39B 'python':32B 'request':56B 'resourc':99C 'self':34B 'self-host':33B 'send':55B 'servic':64B,67B,110C 'starlett':7A,36B,46B,83C,91C 'suscept':96C 'tool':25B 'unbound':59B 'uncontrol':98C 'use':77C 'version':43B,69C,80C,93C,120C 'via':8A 'vulner':4A,42B,79C 'w466':12A,17A 'webui':2A,22A,31B,38B,74C","nicknames":[],"mitigations":[],"who_affected":"Any deployment of Open WebUI older than 0.5.8 that resolves a vulnerable starlette through fastapi is exposed. The exposure depends on the service being reachable by requests, so internet-facing or shared-network instances are the ones to check first. Instances already on 0.5.8 or later with a current fastapi can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2025-03-20T12:32:44+00:00","kev":null,"cvss_vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"GitHub","poc_count":0,"sources":[{"source":"ghsa","external_id":"GHSA-w466-2wfc-8g58","url":"https://github.com/advisories/GHSA-w466-2wfc-8g58","severity":"high","published_at":"2025-03-20T12:32:44+00:00","modified_at":"2026-10-26T15:12:32+00:00","first_seen_at":"2026-10-26T15:12:52+00:00","fetched_at":"2026-10-26T15:18:01+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}