Auth bypass in Open-Webui

CVE-2026-70483

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, DELETE /api/v1/chats/{id} cancelled a chat's in-flight tasks before checking whether the caller could delete that chat. Any authenticated user who knew another user's chat id could abort that user's running model response, title generation, or tag generation, even though the delete was refused and no chat data was deleted, modified, or disclosed. This issue is fixed in 0.11.0.

Vulnerability class: Broken Access Control

EPSS: 0.003 (22.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-70483?
CVE-2026-70483 is a low-severity vulnerability in Open-Webui, classified under Missing Authorization. CVSS score: 3.1/10. Published 2026-08-04.
How severe is CVE-2026-70483?
Low severity. CVSS v3 base score is 3.1 out of 10.