Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, Open WebUI's prompt version-history endpoints authorize the prompt_id in the URL but then act on caller-supplied history IDs without verifying that the history row belongs to that prompt (history_entry.prompt_id == prompt.id). This affects /api/v1/prompts/id/{prompt_id}/history/diff, /api/v1/prompts/id/{prompt_id}/update/version, and /api/v1/prompts/id/{prompt_id}/history/{history_i
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, Open WebUI's prompt version-history endpoints authorize the prompt_id in the URL but then act on caller-supplied history IDs without verifying that the history row belongs to that prompt (history_entry.prompt_id == prompt.id). This affects /api/v1/prompts/id/{prompt_id}/history/diff, /api/v1/prompts/id/{prompt_id}/update/version, and /api/v1/prompts/id/{prompt_id}/history/{history_id}. An authenticated user with access to any prompt they control, plus a victim prompt_history.id, can read or delete another user's private prompt history. This vulnerability is fixed in 0.9.6.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact | 64.00 |
| Exploitation signal(No additional exploitation signal) | ×1.00 |
| VPI | 64.00 |
VPI formula vpi-v1
| Source | CVSS Version | Base Score | Severity | Vector String | Assessment Date |
|---|---|---|---|---|---|
| NVDNIST | 3.1 | 6.4 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L | 06/24/2026 |
| OSV3rd | 3.1 | 6.4 |
| CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L |
| 06/17/2026 |