Skip to content
Fencer Intel
high 8.2

CVE-2026-70486 json

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

published 3mo ago modified last mo. also EUVD-2026-52893 , GHSA-3xpf-xq7r-v8c5 , PYSEC-2026-3641

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi open-webui 0.11.0
  • openwebui open_webui 0.11.0

Is CVE-2026-70486 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-3xpf-xq7r-v8c5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
GitHub 3.1 8.2 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
OSV 3.1 8.2 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi open-webui
>=0.9.0, <0.11.0
0.11.0

Affected products

  • open-webui open-webui

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-1021 Improper Restriction of Rendered UI Layers or Frames

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.