Open WebUI Prompt history IDOR: unbound history_id allows cross-prompt read and deletion

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54015: 0.27% estimated exploitation activity in the next 30 days; percentile 19.15 (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 Open WebUI's prompt version-history endpoints authorize the promptid in the URL but then act on caller-supplied history IDs without verifying that the history row belongs to that prompt (historyentry.promptid == prompt.id). Three operations are affected: - GET /api/v1/prompts/id/{promptid}/history/diff — returns another prompt's history snapshots (read). - POST /api/v1/prompts/id/{promptid}/update/version — restores another prompt's snapshot into the caller's prompt, exposing its content (read). - DELETE /api/v1/prompts/id/{promptid}/history/{historyid} — deletes another prompt's history entry (delete). An authenticated user with access to any prompt they control, plus a victim prompthistory.id, can read or delete another user's private prompt history. The single-entry read endpoint (GET .../history/{historyid}) already enforces the binding; these three did not. Impact Security boundary crossed: prompt confidentiality and integrity. Prompt history snapshots can contain…

Published by the source

17 Jun 2026, 14:16 UTC

Last modified by the source

20 Jul 2026, 21:15 UTC

Source last checked

26 Oct 2026, 13:49 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-4r4w-2wgp-w7cj

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-4r4w-2wgp-w7cj

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# Patch Next advisory brief: CVE-2026-54015

Advisory: Open WebUI Prompt history IDOR: unbound history_id allows cross-prompt read and deletion
IDs: CVE-2026-54015, GHSA-4r4w-2wgp-w7cj
Record: https://patchnext.com/advisories/cve-2026-54015 (revision 2, source checked 26 Oct 2026, 13:49 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: open-webui 0.9.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI open-webui: affected <= 0.9.5; fixed in 0.9.6

## 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-4r4w-2wgp-w7cj (OSV record GHSA-4r4w-2wgp-w7cj lists affected ranges: PyPI open-webui >=0 <0.9.6 (fixed))
- Verified: https://github.com/advisories/GHSA-4r4w-2wgp-w7cj (GitHub-reviewed advisory GHSA-4r4w-2wgp-w7cj lists affected ranges: PyPI open-webui >=0 <=0.9.5)

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