CVE-2026-70486 Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin
An authenticated user can trigger same-origin XSS via terminal file previews to steal session tokens and take over accounts, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-70486?
CVE-2026-70486 is a high-severity cross-site scripting vulnerability in Openwebui Open Webui, published on 4 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, the terminal file-preview serveUrl iframe branch always granted allow-same-origin together with allow-scripts for HTML files served from the application origin. Any authenticated user with access to a configured terminal server could cause script in a previewed file to run in the Open WebUI origin, read the victim's session token from localStorage, and take over the account, with possible server-side code execution if the victim was an admin or held workspace.functions. This issue is fixed in 0.11.0.
Which versions are affected by CVE-2026-70486?
3 open source packages ship an affected version, including open-webui. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
open-webui PyPI | From 0.9.0 | 0.11.0 |
open-webui PyPI | From 0.9.0 | 0.11.0 |
open-webui PyPI | From 0.9.0 | 0.11.0 |
Products include Openwebui Open Webui.
How do I fix CVE-2026-70486?
Upgrade open-webui to 0.11.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-70486 being exploited?
There is no known exploitation of CVE-2026-70486 in the wild and no public exploit code.
Other vulnerabilities in Openwebui Open Webui
- CVE-2026-44551 Open WebUI: LDAP Empty Password Authentication Bypass
- CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
- CVE-2024-8017 Cross-site Scripting (XSS) in open-webui/open-webui
- CVE-2026-45672 Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed
- CVE-2026-87995 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin
Sources
Also known as GHSA-3xpf-xq7r-v8c5, PYSEC-2026-3641.