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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/open-webui/open-webui/commit/5c79ccc9e5c9efc2bc024d8f0b97576…
security-advisories@github.com
https://github.com/open-webui/open-webui/pull/28034
security-advisories@github.com
https://github.com/open-webui/open-webui/releases/tag/v0.11.1
security-advisories@github.com
https://github.com/open-webui/open-webui/security/advisories/GHSA-jqhh-cjmq-vmv6
security-advisories@github.com