Is CVE-2026-109290 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-109290 being exploited in the wild.

How severe is CVE-2026-109290?

High severity, with a CVSS score of 7.3, published 12 October 2026.

Which products and versions are affected?

Open WebUI 0.11.1 through 0.11.3.

How is CVE-2026-109290 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-109290?

Check whether you run Open WebUI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-109290: Open WebUI stored cross-site scripting in DOCX preview

CVE-2026-109290 · Severity: high · CVSS 7.3 · Published 2026-10-12

Open WebUI is a web interface for managing AI models and conversations. Versions 0.11.1 through 0.11.3 contain a vulnerability where authenticated users can upload malicious DOCX files that steal session tokens from other users who preview them. An attacker with basic access can escalate to full administrator control over the instance by stealing an admin's session token, gaining the ability to read all data, change settings, and create unauthorized API keys.

Technologies: Open WebUI. Vendors: Open WebUI.

Quick answers

Is CVE-2026-109290 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-109290 being exploited in the wild.
How severe is CVE-2026-109290?: High severity, with a CVSS score of 7.3, published 12 October 2026.
Which products and versions are affected?: Open WebUI 0.11.1 through 0.11.3.
Is there a fix for CVE-2026-109290?: Yes: fixed in 0.11.4. Until then: Restrict DOCX preview functionality to trusted users only, or disable DOCX attachment previews until the instance can be upgraded to version 0.11.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-109290 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-109290?: Check whether you run Open WebUI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 0.11.4

Restrict DOCX preview functionality to trusted users only, or disable DOCX attachment previews until the instance can be upgraded to version 0.11.4 or later.

Technical details

A stored cross-site scripting vulnerability exists in the DocxPreview.svelte component where DOCX preview rendering does not sanitize embedded HTML parts (OOXML altChunk) or script-scheme hyperlinks. An authenticated attacker can upload a crafted DOCX file containing embedded script that executes in the same origin when another user previews it, allowing theft of the victim's session token from local storage. This requires user interaction (opening the preview) but can escalate an attacker with user-role access to full administrative control when an admin is the victim.

Affected products

Open WebUI Open WebUI 0.11.1 through 0.11.3

Timeline

2026-09-27: disclosed: GitHub security advisory GHSA-f9xp-mfmq-x6cg published
2026-09-27: patched: Fix released in version 0.11.4 via PR #29699
2026-10-12: advisory: CVE-2026-109290 published

References

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