CVE-2026-70483: Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Description

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.

CVSS vector

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

Attack vector

Network

Complexity

Low

Privileges

Low

User interaction

None

Confidentiality

None

Integrity

None

Availability

Low

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.5% · higher than 40% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

OP

open-webui · open-webui

>= 0.9.6, < 0.11.0 · source: vendor

OW

Open Webui · Openwebui

0.9.6 before 0.11.0 · source: NVD