CVE-2026-88002
Open WebUI: Any authenticated user can hang the server via a cyclic chat message history
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-835 |
| Vendor | open-webui |
| Product | open-webui |
| Published | Sep 9, 2026 |
| Last Updated | Sep 14, 2026 |
Stay Ahead of the Next One
Get instant alerts for open-webui open-webui
Be the first to know when new medium vulnerabilities affecting open-webui open-webui are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
open-webui / open-webui
>= 0.5.0, < 0.11.1
References
github.com: https://github.com/open-webui/open-webui/security/advisories/GHSA-jqhh-cjmq-vmv6 github.com: https://github.com/open-webui/open-webui/pull/28034 github.com: https://github.com/open-webui/open-webui/commit/5c79ccc9e5c9efc2bc024d8f0b9757652ece929a github.com: https://github.com/open-webui/open-webui/releases/tag/v0.11.1