# CVE-2026-59221: Open WebUI path traversal bypass in terminal proxy via multi-encoding

Source: https://junglewise.ai/threats/cve-2026-59221-open-webui-path-traversal-bypass-in-terminal-proxy-via-multi  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-09. Updated: 2026-07-25  
License: CC BY 4.0 with a link back

CVE-2026-59221 · Severity: high · CVSS 7.7 · Published 2026-07-09

Open WebUI, a user interface for managing AI models, contains a security flaw in its terminal proxy component. An attacker with standard user access can bypass security filters to access internal system paths or administrative interfaces on the terminal server. This could lead to the exposure of sensitive configuration data or unauthorized access to internal services.

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

## Quick answers

**Is CVE-2026-59221 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-59221 being exploited in the wild.

**How severe is CVE-2026-59221?** High severity, with a CVSS score of 7.7, published 9 July 2026.

**Which products and versions are affected?** open-webui (PyPI) >= 0.9.6, < 0.10.0, ECOSYSTEM:introduced=0.9.6,fixed=0.10.0.

**Is there a fix for CVE-2026-59221?** Yes. open-webui (PyPI): upgrade to 0.10.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-59221 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-59221?** 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 0.10.0 or later

  ```sh
  pip install "open-webui>=0.10.0"
  ```


## Technical details

A path traversal vulnerability exists in the `_sanitize_proxy_path` function within `backend/open_webui/routers/terminals.py`. The sanitizer attempts to prevent traversal by recursively decoding the path up to 8 times using `unquote()`; however, an attacker can use 9 layers of percent-encoding to bypass this limit. Because the 9th layer remains encoded during the security check, `posixpath.normpath()` fails to identify the traversal sequences (e.g., `../`). When the request is subsequently forwarded to the upstream terminal server, the server decodes the remaining layer, allowing the attacker to reach unauthorized paths. This vulnerability is a bypass of the fix previously implemented for GHSA-r2wg-2mcr-66rv.

## Affected products

- open-webui open-webui >= 0.9.6, < 0.10.0

## Identifiers

- CVE-2026-59221
- GHSA-frvj-c5qp-xj4w
- PYSEC-2026-3597

## Timeline

- 2026-07-02: disclosed
- 2026-07-09: advisory: NVD publication
- 2026-07-24: patched: Version 0.10.0 released

## References

- [https://api.github.com/users/DavidCarliez](https://api.github.com/users/DavidCarliez)
- [https://github.com/DavidCarliez](https://github.com/DavidCarliez)
- [https://api.github.com/users/DavidCarliez/gists%7B/gist_id%7D](https://api.github.com/users/DavidCarliez/gists%7B/gist_id%7D)
- [https://api.github.com/users/DavidCarliez/repos](https://api.github.com/users/DavidCarliez/repos)
- [https://avatars.githubusercontent.com/u/271374756?v=4](https://avatars.githubusercontent.com/u/271374756?v=4)
- [https://api.github.com/users/DavidCarliez/events%7B/privacy%7D](https://api.github.com/users/DavidCarliez/events%7B/privacy%7D)

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