Open WebUI missing authorization check at the model update function - models from other users can be updated

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:N/I:H/A:N

EPSS

• CVE-2026-45345: 0.23% estimated exploitation activity in the next 30 days; percentile 13.41 (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 user can modify another user's model even if its visibility is set to Private. The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Open WebUI 0.5.4. Details / PoC The user Victim created a private model with the visibility set to private: The user Attacker can edit this model using the following POST request: Request / Response Impact A user can modify another user's model even if its visibility is set to Private. By changing the access permissions during editing, unauthorized access can be gained.

Published by the source

14 May 2026, 20:21 UTC

Last modified by the source

13 Jul 2026, 16:43 UTC

Source last checked

26 Oct 2026, 13:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-gm54-m39w-grjp

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-gm54-m39w-grjp

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# Patch Next advisory brief: CVE-2026-45345

Advisory: Open WebUI missing authorization check at the model update function - models from other users can be updated
IDs: CVE-2026-45345, GHSA-gm54-m39w-grjp
Record: https://patchnext.com/advisories/cve-2026-45345 (revision 2, source checked 26 Oct 2026, 13:41 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 0.5.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected <= 0.5.6; fixed in 0.5.7

## 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://osv.dev/vulnerability/GHSA-gm54-m39w-grjp (OSV record GHSA-gm54-m39w-grjp lists affected ranges: PyPI open-webui >=0 <0.5.7 (fixed))
- Verified: https://github.com/advisories/GHSA-gm54-m39w-grjp (GitHub-reviewed advisory GHSA-gm54-m39w-grjp lists affected ranges: PyPI open-webui >=0 <=0.5.6)

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