# 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.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** GHSA-4qmj-5jg3-qp9m, GHSA-6fjc-5cg3-mgvh

## 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 (Missing Authorization)

## 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.

## Is CVE-2026-109284 being exploited?

There is no known exploitation of CVE-2026-109284 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109284 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-109284 in the wild and no public exploit code.

Affected product: open-webui. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-109284/ (Markdown: https://insights.sbomify.com/CVE-2026-109284/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109284
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109284
- OSV: https://osv.dev/vulnerability/CVE-2026-109284

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109284/
Summaries are generated and may contain mistakes; the official description above is the record.