CVE-2026-109284 Open WebUI 0.11.0 before 0.11.4 Improper Authorization via Chat Fork Endpoint
Attackers with read-only access can fork chats into shared folders, inserting unauthorized content visible to other users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-109284?
CVE-2026-109284 is a medium-severity missing authorization vulnerability in open-webui, published on 12 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-109284?
How do I fix CVE-2026-109284?
No fix has been published for CVE-2026-109284 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-109284 being exploited?
There is no known exploitation of CVE-2026-109284 in the wild and no public exploit code.
Sources
Also known as GHSA-4qmj-5jg3-qp9m, GHSA-6fjc-5cg3-mgvh.