Categories
CVE-2026-109290 high CVSS 7.3

Cross-Site Scripting (XSS) in Open WebUI (CVE-2026-109290)

Summary

Cross-site scripting in Open WebUI (CVE-2026-109290). Confidential information can be exposed externally.

Original description

The description as published by the source.

Open WebUI from 0.11.1 before 0.11.4 contains a stored cross-site scripting vulnerability in DocxPreview.svelte that allows authenticated users to execute script by uploading crafted DOCX attachments. Attackers can embed an OOXML altChunk HTML part or script-scheme hyperlink to steal a previewing administrator's session token from local storage and take over the instance.

Source: NIST National Vulnerability Database 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-2026-109290 has been found in Open WebUI.
Confidential information can be exposed externally. CVSS score: 7.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Open WebUI CVE-2026-109290" on the vendor's site.

CVE-2026-109290 (Open WebUI) — CWE-79 / CVSS v3 7.3
Attack vector: remote (network-reachable)
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.

❓ What is the problem

Cross-site scripting (XSS) (CWE-79) exists in Open WebUI.

📍 Affected scope

Check the vendor advisory for the affected versions of Open WebUI.

🔥 Severity

Severity: High (CVSS 7.3/10). Confidential information can be exposed externally.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで Open WebUI を使っているサービスとバージョンを洗い出す。

  2. 2
    Post-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。

References

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