Open WebUI Vulnerable to Stored DOM XSS via Note 'Download PDF'

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.7 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

EPSS

• CVE-2025-65959: 0.24% estimated exploitation activity in the next 30 days; percentile 14.51 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A Stored XSS vulnerability has been discovered in Open-WebUI's Notes PDF download functionality. An attacker can import a Markdown file containing malicious SVG tags into Notes, allowing them to execute arbitrary JavaScript code and steal session tokens when a victim downloads the note as PDF. This vulnerability can be exploited by any authenticated user, and unauthenticated external attackers can steal session tokens from users (both admin and regular users) by sharing specially crafted markdown files. Details Vulnerability Location File: src/lib/components/notes/utils.ts Function: downloadPdf() Vulnerable Code (Line 35): Root Cause 1. Incomplete TipTap Editor Configuration - Open-WebUI only uses TipTap StarterKit - No Schema definition for dangerous tags like SVG, Script - Unknown HTML tags are stored as raw HTML 2. Missing Sanitization During PDF Generation - note.data.content.html is directly assigned to innerHTML - No DOMPurify or other sanitization - Stored malicious…

Published by the source

4 Dec 2025, 22:03 UTC

Last modified by the source

5 Dec 2025, 12:36 UTC

Source last checked

26 Oct 2026, 12:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-8wvc-869r-xfqf

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-8wvc-869r-xfqf

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# Patch Next advisory brief: CVE-2025-65959

Advisory: Open WebUI Vulnerable to Stored DOM XSS via Note 'Download PDF'
IDs: CVE-2025-65959, GHSA-8wvc-869r-xfqf
Record: https://patchnext.com/advisories/cve-2025-65959 (revision 2, source checked 26 Oct 2026, 12:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.6.37. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm open-webui: affected <= 0.6.36; fixed in 0.6.37

## Suggested inspection (read-only)
- `npm ls open-webui --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on open-webui.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-8wvc-869r-xfqf (OSV record GHSA-8wvc-869r-xfqf lists affected ranges: npm open-webui >=0 <0.6.37 (fixed))
- Verified: https://github.com/advisories/GHSA-8wvc-869r-xfqf (GitHub-reviewed advisory GHSA-8wvc-869r-xfqf lists affected ranges: npm open-webui >=0 <=0.6.36)

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