Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

CVE-2026-109284Open WebUI 0.11.0 before 0.11.4 Improper Authorization via Chat Fork Endpoint

Medium 4.3

In plain English

A medium-severity missing authorization in open-webui from open-webui. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.2%top 88.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access. Shared folder members downgraded to read-only can call POST /api/v1/chats/{id}/fork on chats they created there while they had write access, inserting attacker-controlled chats visible to the folder owner and members.

Affected products (as reported)

Vendor	Product	Versions
open-webui	open-webui	0.11.0 – before 0.11.4

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

GitHub Security Advisory (GHSA-6fjc-5cg3-mgvh) vendor-advisory
VulnCheck Advisory: Open WebUI 0.11.0 before 0.11.4 Improper Authorization via Chat Fork Endpoint third-party-advisory