Open WebUI: Client-side SSRF via unrestricted external resource loading in Vega/Vega-Lite chart rendering

Exploitation

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

CVSS

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

EPSS

• CVE-2026-70480: 0.35% estimated exploitation activity in the next 30 days; percentile 28.23 (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 Open WebUI renders vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer's browser without a restricted resource loader. Any user who can place such a block where another user will see it can make that user's browser issue attacker-chosen outbound GET requests, and read back responses from same-origin or CORS-permissive targets into the rendered page. Because the request comes from the browser, server-side SSRF protections never see it. Preconditions Default configuration, no flags or environment variables involved: Vega blocks render unconditionally wherever chat content is displayed. The attacker needs an account that can put content in front of the victim, which covers a shared chat, a channel message, and model, RAG or tool output the attacker can influence. The victim must open the message, so this is not zero-click. Deployments where the victim's browser has no network position of interest lose little. Impact The victim's browser…

Published by the source

4 Aug 2026, 19:54 UTC

Last modified by the source

4 Aug 2026, 19:54 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rffm-9q57-q649

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# Patch Next advisory brief: CVE-2026-70480

Advisory: Open WebUI: Client-side SSRF via unrestricted external resource loading in Vega/Vega-Lite chart rendering
IDs: CVE-2026-70480, GHSA-rffm-9q57-q649
Record: https://patchnext.com/advisories/cve-2026-70480 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.11.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected >= 0.6.34, < 0.11.0; fixed in 0.11.0

## Suggested inspection (read-only)
- `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://github.com/advisories/GHSA-rffm-9q57-q649 (GitHub-reviewed advisory GHSA-rffm-9q57-q649 lists affected ranges: PyPI open-webui >=0.6.34 <0.11.0)

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