Open WebUI: Tool source code disclosed to read-only users via the tool list and get endpoints

Exploitation

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

CVSS

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

EPSS

• CVE-2026-70491: 0.48% estimated exploitation activity in the next 30 days; percentile 41.31 (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 workspace tool shared with a read grant returned its full Python source to the recipient. Any authenticated non-admin who could use a shared tool could also read its source, including any user on the instance when a tool was shared publicly. Source is meant to be a writer-only tier: the list response schema deliberately omits it and source export sits behind its own permission. The read endpoints delivered it anyway. Preconditions - Authentication enabled (WEBUIAUTH=true, default) and plugins enabled (ENABLEPLUGINS=true, default). - The attacker is an authenticated non-admin without the workspace.tools permission and without a write grant on the tool. - A tool is shared with a read grant to the attacker, to one of their groups, or to all users (user:). Deployments that share no tools, or share them only with users who already hold write access, are not affected. Impact A non-admin obtains another user's server-side tool source. Tool source commonly embeds hard-coded API…

Published by the source

4 Aug 2026, 20:51 UTC

Last modified by the source

4 Aug 2026, 20:51 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3r7g-q6cg-q2vx

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# Patch Next advisory brief: CVE-2026-70491

Advisory: Open WebUI: Tool source code disclosed to read-only users via the tool list and get endpoints
IDs: CVE-2026-70491, GHSA-3r7g-q6cg-q2vx
Record: https://patchnext.com/advisories/cve-2026-70491 (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 6.5)
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 <= 0.10.2; 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-3r7g-q6cg-q2vx (GitHub-reviewed advisory GHSA-3r7g-q6cg-q2vx lists affected ranges: PyPI open-webui >=0 <=0.10.2)

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