Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels

Exploitation

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

CVSS

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

EPSS

• CVE-2026-44559: 0.22% estimated exploitation activity in the next 30 days; percentile 12.71 (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.

Missing Access Check on Channel Members Endpoint for Standard Channels Affected Component Channel members listing endpoint: - backend/openwebui/routers/channels.py (lines 445-507, getchannelmembersbyid) Affected Versions Current main branch and likely all versions with the channels feature. Description The GET /api/v1/channels/{id}/members endpoint only checks membership for group and dm channel types (lines 467-469). For standard channels — including private ones — there is no channelhasaccess check before returning the member list. Any authenticated user who knows a private channel's UUID can enumerate all users with access to that channel. Compare with other channel endpoints (e.g., getchannelmessages at line 688) which correctly call channelhasaccess(user.id, channel, permission='read') for standard channels. CVSS 3.1 Breakdown | Metric | Value | Rationale | |--------|-------|-----------| | Attack Vector | Network (N) | Exploited remotely via API call | | Attack Complexity | Low…

Published by the source

8 May 2026, 19:51 UTC

Last modified by the source

13 Jul 2026, 16:42 UTC

Source last checked

26 Oct 2026, 13:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-c7wp-3qh5-55pv

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-c7wp-3qh5-55pv

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# Patch Next advisory brief: CVE-2026-44559

Advisory: Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels
IDs: CVE-2026-44559, GHSA-c7wp-3qh5-55pv
Record: https://patchnext.com/advisories/cve-2026-44559 (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 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected <= 0.8.12; fixed in 0.9.0

## 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://osv.dev/vulnerability/GHSA-c7wp-3qh5-55pv (OSV record GHSA-c7wp-3qh5-55pv lists affected ranges: PyPI open-webui >=0 <0.9.0 (fixed))
- Verified: https://github.com/advisories/GHSA-c7wp-3qh5-55pv (GitHub-reviewed advisory GHSA-c7wp-3qh5-55pv lists affected ranges: PyPI open-webui >=0 <=0.8.12)

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