Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-70486

CVE-2026-70486MEDIUM

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

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   L   R  C  L  L  N    5.4   .0038   29.6     —

AFFECTED
  Product     Versions              Fixed
  open-webui  >= 0.9.0, < 0.11.0 –  —

TIMELINE
  Aug 4   Reserved by GitHub_M
  Aug 4   Published (CNA: GitHub_M)
  Sep 18  EXPLOIT PUBLISHED — CVE-2026-70486 (open-webui). Public exploit reference added.
  Sep 18  RESCORED — CVE-2026-70486 (open-webui). CVSS 8.2 → 5.4 (NVD).

CWE-79, CWE-1021 · CNA: GitHub_M · CVSS v3.1 · 4 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
August 4, 2026	Reserved	Reserved by GitHub_M
August 4, 2026	Published	Published (CNA: GitHub_M)
September 18, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-70486 (open-webui). Public exploit reference added.
September 18, 2026	RESCORED	RESCORED — CVE-2026-70486 (open-webui). CVSS 8.2 → 5.4 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
open-webui	open-webui	—	>= 0.9.0, < 0.11.0	—

Weaknesses

CWE-79 · CWE-1021

References (4)

https://github.com/open-webui/open-webui/commit/65a5fad7b97db99d490d81f4e0860282c3a4543c [Patch]
https://github.com/open-webui/open-webui/pull/26907 [Patch, Vendor Advisory]
https://github.com/open-webui/open-webui/releases/tag/v0.11.0 [Release Notes]
https://github.com/open-webui/open-webui/security/advisories/GHSA-3xpf-xq7r-v8c5 [Exploit, Patch, Vendor Advisory]

Authoritative record: CVE-2026-70486 at cve.org

Vendors: open-webui

Weaknesses: CWE-79 · CWE-1021

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-70486 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.