# CVE-2026-88002: Open WebUI: Any authenticated user can hang the server via a cyclic chat message history

> An authenticated user can cause a denial of service in Open WebUI by creating cyclic chat messages that hang the server.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-jqhh-cjmq-vmv6, PYSEC-2026-3879

## What is CVE-2026-88002?

CVE-2026-88002 is a medium-severity denial of service vulnerability in Openwebui Open Webui, published on 9 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.5.0 until 0.11.1, the message-chain reconstruction helper in backend/open_webui/utils/misc.py advanced through a chat history by map key but tracked visited entries using each message body's optional id field. An authenticated user could store id-less messages in a parent cycle and trigger a non-terminating walk that blocked the async event loop, grew memory until termination, and remained persistent across process restarts. This issue is fixed in version 0.11.1.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-88002?

3 open source packages ship an affected version, including open-webui. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `open-webui` | PyPI | From 0.5.0 | 0.11.1 |
| `open-webui` | PyPI | From 0.5.0 | 0.11.1 |
| `open-webui` | PyPI | From 0.5.0 | 0.11.1 |

Products: Openwebui Open Webui.

## How do I fix CVE-2026-88002?

Upgrade open-webui to 0.11.1 or later.

## Is CVE-2026-88002 being exploited?

There is no known exploitation of CVE-2026-88002 in the wild and no public exploit code.

## Other vulnerabilities in Openwebui Open Webui

- [CVE-2026-44551](https://insights.sbomify.com/CVE-2026-44551/): Open WebUI: LDAP Empty Password Authentication Bypass (critical 9.1)
- [CVE-2026-56400](https://insights.sbomify.com/CVE-2026-56400/): open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation (critical 9.0)
- [CVE-2024-8017](https://insights.sbomify.com/CVE-2024-8017/): Cross-site Scripting (XSS) in open-webui/open-webui (critical 9.0)
- [CVE-2026-45672](https://insights.sbomify.com/CVE-2026-45672/): Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed (high 8.8)
- [CVE-2026-87995](https://insights.sbomify.com/CVE-2026-87995/): Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88002 and fix it if it is affected.

What it is: CVE-2026-88002 is a medium-severity denial of service vulnerability in Openwebui Open Webui, published on 9 Sep 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-2026-88002 in the wild and no public exploit code.

Affected packages and fixed versions:
- open-webui (PyPI): affected from 0.5.0; fixed in 0.11.1
- open-webui (PyPI): affected from 0.5.0; fixed in 0.11.1
- open-webui (PyPI): affected from 0.5.0; fixed in 0.11.1

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-2026-88002/ (Markdown: https://insights.sbomify.com/CVE-2026-88002/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88002
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88002
- OSV: https://osv.dev/vulnerability/CVE-2026-88002

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88002/
Summaries are generated and may contain mistakes; the official description above is the record.