Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Exploitation

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

CVSS

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

EPSS

• CVE-2026-70483: 0.46% estimated exploitation activity in the next 30 days; percentile 39.74 (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 DELETE /api/v1/chats/{id} cancelled a chat's in-flight tasks before it checked whether the caller was allowed to delete that chat. Any authenticated user who knew another user's chat id could therefore abort that user's running model response, title generation or tag generation. The deletion itself was still refused, so the only missing control was on the cancellation side effect. Preconditions Default configuration, no special deployment shape. The attacker needs a normal account with the default user role and nothing else: the chat.delete permission is not required, and revoking it does not prevent the cancellation. The attacker also needs the victim's chat id, which is returned by the read-only shared-chat endpoint when a chat or a folder has been shared with them - otherwise enumerating the chat id requires guessing the chat id or brute forcing it, and the victim must have a generation running at that moment. Impact A user can repeatedly interrupt another user's…

Published by the source

4 Aug 2026, 19:54 UTC

Last modified by the source

5 Aug 2026, 04:28 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3vf6-64vr-3g56

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# Patch Next advisory brief: CVE-2026-70483

Advisory: Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint
IDs: CVE-2026-70483, GHSA-3vf6-64vr-3g56
Record: https://patchnext.com/advisories/cve-2026-70483 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.11.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected >= 0.9.6, < 0.11.0; fixed in 0.11.0

## 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://github.com/advisories/GHSA-3vf6-64vr-3g56 (GitHub-reviewed advisory GHSA-3vf6-64vr-3g56 lists affected ranges: PyPI open-webui >=0.9.6 <0.11.0)

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