Cross-Site Scripting (XSS) in open-webui (CVE-2026-70486)
Summary
Cross-site scripting in open-webui (CVE-2026-70486). Confidential information can be exposed externally. Exploitable via TERMINAL_SERVER_CONNECTIONS. Mitigation: upgrade to 0.11.0 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-70486 has been found in open-webui.
Attackers can target a specific entry point like TERMINAL_SERVER_CONNECTIONS over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.2/10.
What to do: upgrade open-webui to 0.11.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-70486" on the vendor's site.
CVE-2026-70486 (open-webui) — CWE-79 / CVSS v3 8.2
Attack vector: remote (network-reachable) / no user interaction
Attack surface: TERMINAL_SERVER_CONNECTIONS / display_file / TERMINAL_PROXY_HEADERS / iframeSandboxAllowSameOrigin
Patched: 0.11.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in open-webui. Attackers reach the vulnerable code path via TERMINAL_SERVER_CONNECTIONS.
Check the vendor advisory for the affected versions of open-webui. Attack surface: TERMINAL_SERVER_CONNECTIONS / display_file / TERMINAL_PROXY_HEADERS / iframeSandboxAllowSameOrigin.
Severity: High (CVSS 8.2/10). Confidential information can be exposed externally.
Update to 0.11.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'open-webui' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'open-webui' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
open-webuiを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade open-webui to 0.11.0ステージング環境で 0.11.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- package pypi.org
- patch github.com
- patch github.com
- web github.com