PT-2026-59370 · Pypi · Open-Webui

Published

2026-07-13

·

Updated

2026-07-13

CVSS v3.1

4.3

Medium

VectorAV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Summary

When setting model permissions so that a group has read access to it, intending for other users to use it, those users also can read the model's system prompt.
However users may consider their system prompt confidential, so we consider this a security issue.
Compare https://genai.owasp.org/llmrisk/llm072025-system-prompt-leakage/ or prompt injections to get popular chatbots on the internet to reveal their prompt.

Details

We discovered that users can open the workspace model edit page /workspace/models/edit?id=notmymodel for models that do not appear in their workspace.
Saving is not possible, that permission check is correct.
On the API level:
  • /api/v1/models/model?id=notmymodel -> returns the model details, most importantly params.system
  • even though /api/v1/models/list does NOT contain the model since it checks for write permission.
  • /api/models contains the model correctly and does not reveal the system prompt.
It seems inconsistent that the REST API list does not contain an item, but if you know the id, you can access it anyway.

PoC

  • create model
  • give read permission to group with another user
  • other user can access /api/v1/models/model?id=notmymodel

Impact

System prommpt leakage
If this is intended behavior for the "read" permission, maybe there should be an additional "use" permission (which would be 99% of use cases of the read permission i believe).

Fix

Found an issue in the description? Have something to add? Feel free to write us 👾

Related Identifiers

PYSEC-2026-2728

Affected Products

Open-Webui