{"id":"CVE-2026-59214","aliases":["EUVD-2026-42616","GHSA-4r2p-27mh-5m22","PYSEC-2026-3590"],"status":"published","title":"Open WebUI: Stored web worker XSS via Pyodide","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.10.0, Open WebUI runs client-side Python with Pyodide in a same-origin web worker, allowing stored chat payloads that use pyodide.http.pyfetch or the js module fetch and XMLHttpRequest APIs to issue authenticated same-origin requests when a victim clicks Run, which can reach admin-only endpoints and execute server-side code through configured tools. This issue is fixed in version 0.10.0.","severity":{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00423,"percentile":0.36953,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2026-07-09T15:51:38Z","modified":"2026-10-28T02:30:37Z","fixes":[{"ecosystem":"PyPI","package":"open-webui","fixed_in":["0.10.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"open-webui","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"open-webui","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.0"}]}],"versions":["0.1.124","0.1.125","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.10","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.17.dev2","0.3.17.dev3","0.3.17.dev4","0.3.17.dev5","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.27.dev1","0.3.27.dev2","0.3.27.dev3","0.3.28","0.3.29","0.3.3","0.3.30","0.3.30.dev1","0.3.30.dev2","0.3.31","0.3.31.dev1","0.3.32","0.3.33","0.3.33.dev1","0.3.34","0.3.35","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.0.dev1","0.4.0.dev2","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.6.dev1","0.4.7","0.4.8","0.5.0","0.5.0.dev1","0.5.0.dev2","0.5.1","0.5.10","0.5.11","0.5.12","0.5.13","0.5.14","0.5.15","0.5.16","0.5.17","0.5.18","0.5.19","0.5.2","0.5.20","0.5.3","0.5.3.dev1","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.15","0.6.16","0.6.18","0.6.19","0.6.2","0.6.20","0.6.21","0.6.22","0.6.23","0.6.24","0.6.25","0.6.26","0.6.26.dev1","0.6.27","0.6.28","0.6.29","0.6.3","0.6.30","0.6.31","0.6.32","0.6.33","0.6.34","0.6.35","0.6.36","0.6.37","0.6.38","0.6.39","0.6.4","0.6.40","0.6.41","0.6.42","0.6.43","0.6.5","0.6.6","0.6.6.dev1","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.8.0","0.8.1","0.8.10","0.8.11","0.8.12","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9","0.9.0","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6"]},{"source":"osv","ecosystem":"PyPI","package":"open-webui","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.10.0"}]}],"versions":["0.1.124","0.1.125","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.10","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.17.dev2","0.3.17.dev3","0.3.17.dev4","0.3.17.dev5","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.27.dev1","0.3.27.dev2","0.3.27.dev3","0.3.28","0.3.29","0.3.3","0.3.30","0.3.30.dev1","0.3.30.dev2","0.3.31","0.3.31.dev1","0.3.32","0.3.33","0.3.33.dev1","0.3.34","0.3.35","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.0.dev1","0.4.0.dev2","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.6.dev1","0.4.7","0.4.8","0.5.0","0.5.0.dev1","0.5.0.dev2","0.5.1","0.5.10","0.5.11","0.5.12","0.5.13","0.5.14","0.5.15","0.5.16","0.5.17","0.5.18","0.5.19","0.5.2","0.5.20","0.5.3","0.5.3.dev1","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.15","0.6.16","0.6.18","0.6.19","0.6.2","0.6.20","0.6.21","0.6.22","0.6.23","0.6.24","0.6.25","0.6.26","0.6.26.dev1","0.6.27","0.6.28","0.6.29","0.6.3","0.6.30","0.6.31","0.6.32","0.6.33","0.6.34","0.6.35","0.6.36","0.6.37","0.6.38","0.6.39","0.6.4","0.6.40","0.6.41","0.6.42","0.6.43","0.6.5","0.6.6","0.6.6.dev1","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.8.0","0.8.1","0.8.10","0.8.11","0.8.12","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9","0.9.0","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6"]}],"products":[{"vendor":"open-webui","product":"open-webui"},{"vendor":"openwebui","product":"open_webui"}],"references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-4r2p-27mh-5m22","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59214","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4r2p-27mh-5m22","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59214.json","tags":["advisory"]},{"url":"https://github.com/open-webui/open-webui","tags":["package"]},{"url":"https://pypi.org/project/open-webui","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-59214","title":"Open WebUI: Stored web worker XSS via Pyodide","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.10.0, Open WebUI runs client-side Python with Pyodide in a same-origin web worker, allowing stored chat payloads that use pyodide.http.pyfetch or the js module fetch and XMLHttpRequest APIs to issue authenticated same-origin requests when a victim clicks Run, which can reach admin-only endpoints and execute server-side code through configured tools. This issue is fixed in version 0.10.0.","status":"published","published":"2026-07-09T15:51:38.001Z","modified":"2026-07-09T17:13:10.879Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:19:58.560602Z"}],"euvd":[{"id":"EUVD-2026-42616","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.10.0, Open WebUI runs client-side Python with Pyodide in a same-origin web worker, allowing stored chat payloads that use pyodide.http.pyfetch or the js module fetch and XMLHttpRequest APIs to issue authenticated same-origin requests when a victim clicks Run, which can reach admin-only endpoints and execute server-side code through configured tools. This issue is fixed in version 0.10.0.","status":"published","published":"2026-07-09T15:51:38Z","modified":"2026-07-09T17:13:10Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:20:03.742277Z"}],"ghsa":[{"id":"GHSA-4r2p-27mh-5m22","title":"Open WebUI: Stored web worker XSS via Pyodide","description":"**Title:** Same-origin Pyodide code execution allows server-side RCE via a shared chat\n\n### Summary\n\nOpen 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**.\n\n### Details\n\nPyodide'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.\n\n```python\nfrom pyodide.http import pyfetch\nimport json\nawait pyfetch('/api/v1/functions/create', method='POST', credentials='include',\n              headers={'Content-Type': 'application/json'},\n              body=json.dumps({'id': 'x', 'name': 'x', 'meta': {'description': 'x'},\n                               'content': \"import os; os.system('\u003cattacker command\u003e')\"}))\n```\n\n### Impact\n\nWhen the victim runs the shared code, an authenticated low-privileged user achieves remote code execution on the server (the created Function/Tool runs server-side Python) if the victim is an admin or holds `workspace.functions` / `workspace.tools` permissions. More generally the executed code can issue any authenticated request as the victim. Requires the victim to click Run, and Open WebUI configured to use Pyodide.\n\n### Patched\n\nPyodide now runs in a sandboxed iframe at an opaque origin by default (`sandbox=\"allow-scripts\"`, no `allow-same-origin`). At an opaque origin `pyfetch`, `fetch` and `XMLHttpRequest` to the app become cross-origin requests that carry no session cookie and are CORS-blocked, and the `js` bridge operates on the isolated iframe window with no access to the parent's cookie, token, `localStorage` or DOM. Full Python, JavaScript and external fetch keep working. IDBFS persistence is available only behind `ENABLE_PYODIDE_FILE_PERSISTENCE=true`, which restores the same-origin worker and re-accepts this risk.\n\n### Workaround\n\nUntil upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option.\n\n### Credits\n\n@gg0h","status":"published","published":"2026-07-24T16:54:40Z","modified":"2026-07-24T16:54:42Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:40:52.46233Z"}],"nvd":[{"id":"CVE-2026-59214","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.10.0, Open WebUI runs client-side Python with Pyodide in a same-origin web worker, allowing stored chat payloads that use pyodide.http.pyfetch or the js module fetch and XMLHttpRequest APIs to issue authenticated same-origin requests when a victim clicks Run, which can reach admin-only endpoints and execute server-side code through configured tools. This issue is fixed in version 0.10.0.","status":"published","published":"2026-07-09T17:17:02.177Z","modified":"2026-07-10T19:24:29.937Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:28.4135Z"}],"osv":[{"id":"CVE-2026-59214","title":"Open WebUI: Stored web worker XSS via Pyodide","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.10.0, Open WebUI runs client-side Python with Pyodide in a same-origin web worker, allowing stored chat payloads that use pyodide.http.pyfetch or the js module fetch and XMLHttpRequest APIs to issue authenticated same-origin requests when a victim clicks Run, which can reach admin-only endpoints and execute server-side code through configured tools. This issue is fixed in version 0.10.0.","status":"published","published":"2026-07-09T15:51:38.001Z","modified":"2026-10-28T02:30:37.083584147Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:12.496548Z"},{"id":"GHSA-4r2p-27mh-5m22","title":"Open WebUI: Stored web worker XSS via Pyodide","description":"**Title:** Same-origin Pyodide code execution allows server-side RCE via a shared chat\n\n### Summary\n\nOpen 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**.\n\n### Details\n\nPyodide'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.\n\n```python\nfrom pyodide.http import pyfetch\nimport json\nawait pyfetch('/api/v1/functions/create', method='POST', credentials='include',\n              headers={'Content-Type': 'application/json'},\n              body=json.dumps({'id': 'x', 'name': 'x', 'meta': {'description': 'x'},\n                               'content': \"import os; os.system('\u003cattacker command\u003e')\"}))\n```\n\n### Impact\n\nWhen the victim runs the shared code, an authenticated low-privileged user achieves remote code execution on the server (the created Function/Tool runs server-side Python) if the victim is an admin or holds `workspace.functions` / `workspace.tools` permissions. More generally the executed code can issue any authenticated request as the victim. Requires the victim to click Run, and Open WebUI configured to use Pyodide.\n\n### Patched\n\nPyodide now runs in a sandboxed iframe at an opaque origin by default (`sandbox=\"allow-scripts\"`, no `allow-same-origin`). At an opaque origin `pyfetch`, `fetch` and `XMLHttpRequest` to the app become cross-origin requests that carry no session cookie and are CORS-blocked, and the `js` bridge operates on the isolated iframe window with no access to the parent's cookie, token, `localStorage` or DOM. Full Python, JavaScript and external fetch keep working. IDBFS persistence is available only behind `ENABLE_PYODIDE_FILE_PERSISTENCE=true`, which restores the same-origin worker and re-accepts this risk.\n\n### Workaround\n\nUntil upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option.\n\n### Credits\n\n@gg0h","status":"published","published":"2026-07-24T16:54:40Z","modified":"2026-08-04T14:40:41.11451692Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:37.528068Z"},{"id":"PYSEC-2026-3590","title":"Open WebUI: Stored web worker XSS via Pyodide","description":"**Title:** Same-origin Pyodide code execution allows server-side RCE via a shared chat\n\n### Summary\n\nOpen 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**.\n\n### Details\n\nPyodide'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.\n\n```python\nfrom pyodide.http import pyfetch\nimport json\nawait pyfetch('/api/v1/functions/create', method='POST', credentials='include',\n              headers={'Content-Type': 'application/json'},\n              body=json.dumps({'id': 'x', 'name': 'x', 'meta': {'description': 'x'},\n                               'content': \"import os; os.system('\u003cattacker command\u003e')\"}))\n```\n\n### Impact\n\nWhen the victim runs the shared code, an authenticated low-privileged user achieves remote code execution on the server (the created Function/Tool runs server-side Python) if the victim is an admin or holds `workspace.functions` / `workspace.tools` permissions. More generally the executed code can issue any authenticated request as the victim. Requires the victim to click Run, and Open WebUI configured to use Pyodide.\n\n### Patched\n\nPyodide now runs in a sandboxed iframe at an opaque origin by default (`sandbox=\"allow-scripts\"`, no `allow-same-origin`). At an opaque origin `pyfetch`, `fetch` and `XMLHttpRequest` to the app become cross-origin requests that carry no session cookie and are CORS-blocked, and the `js` bridge operates on the isolated iframe window with no access to the parent's cookie, token, `localStorage` or DOM. Full Python, JavaScript and external fetch keep working. IDBFS persistence is available only behind `ENABLE_PYODIDE_FILE_PERSISTENCE=true`, which restores the same-origin worker and re-accepts this risk.\n\n### Workaround\n\nUntil upgraded, disable Pyodide code execution or set the Code Execution / Code Interpreter engine to a server-side option.\n\n### Credits\n\n@gg0h","status":"published","published":"2026-08-04T11:34:42.338553Z","modified":"2026-08-04T14:30:17.752429795Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:52:56.847083Z"}]}}