open-webui Vulnerable to Stored XSS via Model Description

Exploitation

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

CVSS

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

EPSS

• CVE-2026-44721: 0.31% estimated exploitation activity in the next 30 days; percentile 23.64 (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.

[!IMPORTANT] Relationship to CVE-2024-7990 CVE-2024-7990 (issued by huntr.dev, March 2025) describes a stored XSS in the same field — the model description — but exploits a different bypass mechanism: a second-order injection through the sanitizeResponseContent function's video-tag placeholder restoration logic in v0.3.x. That bypass was closed in v0.4.0 by removing the video exemption from the sanitizer. The vulnerability described in this advisory is structurally distinct: a markdown-link payload with a javascript: URI passes through sanitizeResponseContent unchanged (no angle brackets), is then parsed by marked.parse() into an <a href="javascript:..." element, and rendered live by {@html}. This is a pipeline-ordering flaw where the dangerous construct is introduced after sanitization completes. Removing the video exemption has no effect on this primitive. Affected range: v0.3.5 through v0.8.12 inclusive. Fixed in: v0.9.0 (commit 5eab125, which wraps marked.parse() output in…

Published by the source

8 May 2026, 19:00 UTC

Last modified by the source

13 Jul 2026, 16:42 UTC

Source last checked

26 Oct 2026, 12:52 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-gf5m-wcrh-7928

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-gf5m-wcrh-7928

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# Patch Next advisory brief: CVE-2026-44721

Advisory: open-webui Vulnerable to Stored XSS via Model Description
IDs: CVE-2026-44721, GHSA-gf5m-wcrh-7928
Record: https://patchnext.com/advisories/cve-2026-44721 (revision 2, source checked 26 Oct 2026, 12:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.9.0; open-webui 0.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm open-webui: affected <= 0.8.12; fixed in 0.9.0
- PyPI open-webui: affected <= 0.8.12; fixed in 0.9.0

## 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`.
- `python -m pip show open-webui`: prints the installed version. Run with the environment that serves production active.

## 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-gf5m-wcrh-7928 (OSV record GHSA-gf5m-wcrh-7928 lists affected ranges: npm open-webui >=0 =0 <0.9.0 (fixed))
- Verified: https://github.com/advisories/GHSA-gf5m-wcrh-7928 (GitHub-reviewed advisory GHSA-gf5m-wcrh-7928 lists affected ranges: npm open-webui >=0 =0 <=0.8.12)

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