# CVE-2026-70491: Open WebUI tool source code disclosure to read-only users

Source: https://junglewise.ai/threats/cve-2026-70491-open-webui-tool-source-code-disclosure-to-read-only-users  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-04. Updated: 2026-08-04  
License: CC BY 4.0 with a link back

CVE-2026-70491 · Severity: medium · CVSS 6.5 · Published 2026-08-04

Open WebUI is a user interface for interacting with large language models. A security flaw allowed users with basic access to view the full Python source code of shared workspace tools, which they should only be able to use, not read. This is a significant risk because tool source code often contains sensitive information like API keys, internal service URLs, and credentials.

Technologies: [open-webui (PyPI)](https://junglewise.ai/threats/technologies/open-webui). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-70491 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-70491 being exploited in the wild.

**How severe is CVE-2026-70491?** Medium severity, with a CVSS score of 6.5, published 4 August 2026.

**Which products and versions are affected?** open-webui (PyPI) <= 0.10.2, ECOSYSTEM:introduced=0,fixed=0.11.0.

**Is there a fix for CVE-2026-70491?** Yes. open-webui (PyPI): upgrade to 0.11.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-70491 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-70491?** Check whether you run open-webui (PyPI) 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

- open-webui (PyPI): upgrade to 0.11.0 or later

  ```sh
  pip install "open-webui>=0.11.0"
  ```


## Technical details

An information disclosure vulnerability exists in Open WebUI's tool management API. The root cause is an insecure response model implementation where the 'ToolUserResponse' subclass permitted extra fields, causing the full tool model (including source code) to be serialized and returned to the caller even when the schema was intended to omit it. Additionally, the listing logic failed to properly filter source code from database queries. An authenticated attacker with read access to a tool can retrieve its full source code via the GET /api/v1/tools/, /api/v1/tools/list, or /api/v1/tools/id/{id} endpoints. This vulnerability is fixed in version 0.11.0.

## Affected products

- Open WebUI open-webui <= 0.10.2

## Identifiers

- CVE-2026-70491
- GHSA-3r7g-q6cg-q2vx
- PYSEC-2026-3639

## Timeline

- 2026-08-02: patched: Fix released in version 0.11.0
- 2026-08-04: disclosed: Public advisory published

## References

- [https://api.github.com/users/bogdancherniy11-sudo](https://api.github.com/users/bogdancherniy11-sudo)
- [https://github.com/bogdancherniy11-sudo](https://github.com/bogdancherniy11-sudo)
- [https://api.github.com/users/bogdancherniy11-sudo/gists%7B/gist_id%7D](https://api.github.com/users/bogdancherniy11-sudo/gists%7B/gist_id%7D)
- [https://api.github.com/users/bogdancherniy11-sudo/repos](https://api.github.com/users/bogdancherniy11-sudo/repos)
- [https://avatars.githubusercontent.com/u/229690748?v=4](https://avatars.githubusercontent.com/u/229690748?v=4)
- [https://api.github.com/users/bogdancherniy11-sudo/events%7B/privacy%7D](https://api.github.com/users/bogdancherniy11-sudo/events%7B/privacy%7D)

## Related threats

- [Open WebUI OAuth token exchange authorization bypass](https://junglewise.ai/threats/cve-2026-88006-open-webui-oauth-token-exchange-authorization-bypass)
- [Open WebUI OAuth token exchange authorization bypass](https://junglewise.ai/threats/cve-2026-88005-open-webui-oauth-token-exchange-authorization-bypass)
- [Open WebUI infinite loop denial of service in chat history reconstruction](https://junglewise.ai/threats/cve-2026-88002-open-webui-infinite-loop-denial-of-service-in-chat-history)
- [Open WebUI server-side request forgery via unvalidated HTTP redirects](https://junglewise.ai/threats/cve-2026-88001-open-webui-server-side-request-forgery-via-unvalidated-http)
- [Open WebUI denial of service via cyclic chat tree message deletion](https://junglewise.ai/threats/cve-2026-88000-open-webui-denial-of-service-via-cyclic-chat-tree-message)