Open WebUI has an IDOR vulnerability in the update_message_by_id API endpoint

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:N/I:L/A:N

EPSS

• CVE-2026-45385: 0.25% estimated exploitation activity in the next 30 days; percentile 16.44 (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 An IDOR vulnerability exists in the Channels feature of Open WebUI, allowing any channel member to modify messages sent by other members (including administrators) within the same channel. This vulnerability affects the latest version (v0.8.12) of Open WebUI. Details In the updatemessagebyid function, for group or dm type channels, only the caller's membership in the channel is checked via the isuserchannelmember function, without verifying message ownership. This allows any channel member to modify messages sent by other members within the same channel. The problematic code is as follows (https://github.com/open-webui/open-webui/blob/main/backend/openwebui/routers/channels.py#L1355) : Non-group/dm types include a check for the user ID, while the group/dm type clearly lacks this verification. PoC The Channels feature is disabled by default and can be enabled first through the admin interface. <img width="1024" height="618" alt="image"…

Published by the source

14 May 2026, 20:25 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-wwhq-cx22-f7vv

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-wwhq-cx22-f7vv

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# Patch Next advisory brief: CVE-2026-45385

Advisory: Open WebUI has an IDOR vulnerability in the update_message_by_id API endpoint
IDs: CVE-2026-45385, GHSA-wwhq-cx22-f7vv
Record: https://patchnext.com/advisories/cve-2026-45385 (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 0.9.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected < 0.9.5; fixed in 0.9.5

## 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-wwhq-cx22-f7vv (OSV record GHSA-wwhq-cx22-f7vv lists affected ranges: PyPI open-webui >=0 <0.9.5 (fixed))
- Verified: https://github.com/advisories/GHSA-wwhq-cx22-f7vv (GitHub-reviewed advisory GHSA-wwhq-cx22-f7vv lists affected ranges: PyPI open-webui >=0 <0.9.5)

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