Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin

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.

Scores

EPSS (exploitation in 30 days)

0.38% · top 68% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.

Weakness

• CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)All about CWE-79 and its CVEs
• CWE-1021: Improper Restriction of Rendered UI Layers or Frames (opens in a new tab)All about CWE-1021 and its CVEs

Affected products

• open-webui · open-webui

  • affected >= 0.9.0, < 0.11.0

Affected packages

From reviewed advisories of the GitHub Advisory Database.

• PyPIopen-webuiGHSA-3xpf-xq7r-v8c5 (opens in a new tab)

References (4)

• https://github.com/open-webui/open-webui/security/advisories/GHSA-3xpf-xq7r-v8c5 (opens in a new tab)x_refsource_CONFIRM
• https://github.com/open-webui/open-webui/pull/26907 (opens in a new tab)x_refsource_MISC
• https://github.com/open-webui/open-webui/commit/65a5fad7b97db99d490d81f4e0860282c3a4543c (opens in a new tab)x_refsource_MISC
• https://github.com/open-webui/open-webui/releases/tag/v0.11.0 (opens in a new tab)x_refsource_MISC

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisory GHSA-3xpf-xq7r-v8c5 (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-70486](https://trackcve.app/badge/CVE-2026-70486.svg)](https://trackcve.app/cve/CVE-2026-70486)

Record last updated 5 Aug 2026, 14:29 UTC.