The vulnerability of the /oauth/backchannel-logout web interface based on artificial intelligence in Open WebUI allows a perpetrator to trigger a service failure.

The vulnerability of the /oauth/backchannel-logout web interface component in the Open WebUI system is related to asymmetric resource consumption. Exploiting this vulnerability could allow a malicious actor to cause service failure remotely...

EUVD-2026-75185

Open WebUI: Any authenticated user can hang the server via message deletion in a cyclic chat tree...

Open WebUI: Any authenticated user can hang the server via message deletion in a cyclic chat tree

Summary Chat histories are stored as an unvalidated JSON object. After a message is deleted, the code that picks the chat's new current message walked down the childrenIds links without recording where it had already been. Any account with the default user role could store a chat whose messages...

GHSA-3CGP-3CQX-J8W2 Open WebUI: Any authenticated user can hang the server via message deletion in a cyclic chat tree

Summary Chat histories are stored as an unvalidated JSON object. After a message is deleted, the code that picks the chat's new current message walked down the childrenIds links without recording where it had already been. Any account with the default user role could store a chat whose messages...

Infinite loop

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Infinite loop through the chat-history message deletion helper process. An attacker can cause the server to hang and deny service to all users by creating a cyclic chat tree and deleting a message, resulting ...

EUVD-2026-75187

Open WebUI: Server-side fetches reach blocked and internal hosts via unvalidated HTTP redirect targets...

Open WebUI: Server-side fetches reach blocked and internal hosts via unvalidated HTTP redirect targets

Summary Open WebUI protects server-side web fetches with two controls: the operator's list of excluded hosts, and a check that refuses private and internal addresses. Neither control was applied to the destination of an HTTP redirect. On a deployment where redirect following is enabled, any...

GHSA-5X7X-4C3C-QF5W Open WebUI: Server-side fetches reach blocked and internal hosts via unvalidated HTTP redirect targets

Summary Open WebUI protects server-side web fetches with two controls: the operator's list of excluded hosts, and a check that refuses private and internal addresses. Neither control was applied to the destination of an HTTP redirect. On a deployment where redirect following is enabled, any...

Server-side Request Forgery (SSRF)

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Server-side Request Forgery SSRF in the fetch process when HTTP redirects are followed and the destination of the redirect is not validated against excluded hosts or private/internal address checks. An attack...

EUVD-2026-75188

Open WebUI: Any authenticated user can hang the server via a cyclic chat message history...

Open WebUI: Any authenticated user can hang the server via a cyclic chat message history

Summary Chat histories are stored as an unvalidated JSON object. The walk that reconstructs a chat's message chain detected repeats using each message's own id field while moving through the history by map key, so a message that simply omitted id was never recorded as visited. A history whose...

GHSA-JQHH-CJMQ-VMV6 Open WebUI: Any authenticated user can hang the server via a cyclic chat message history

Summary Chat histories are stored as an unvalidated JSON object. The walk that reconstructs a chat's message chain detected repeats using each message's own id field while moving through the history by map key, so a message that simply omitted id was never recorded as visited. A history whose...

Infinite loop

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Infinite loop in the message-chain reconstruction process. An attacker can cause the server to hang and consume excessive resources by submitting a chat history with cyclic parent references and omitted id...

CVE-2026-88002

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/openwebui/utils/misc.py advanced through a chat history by map key but tracked visited entries using each message body's optional id...

CVE-2026-88000

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, DELETE /api/v1/chats/id/messages/messageid used the chat-history deletion helper in backend/openwebui/models/chats.py to follow childrenIds without recording visited message identifiers...

CVE-2026-87997

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, POST /api/chat/completions and POST /api/v1/chat/completions in backend/openwebui/main.py copied a client-supplied folderid into a new chat without applying the folder write-access chec...

CVE-2026-87998

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, DELETE /api/v1/knowledge/id/delete in backend/openwebui/routers/knowledge.py authorized deletion against the knowledge base but then removed its administrator-owned external connection...

CVE-2026-87999

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.11.1, POST /api/v1/retrieval/process/web and POST /api/v1/retrieval/process/web/search in backend/openwebui/retrieval/web/utils.py treated Python's globally routable address classification as proof th...

CVE-2026-88001

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 until 0.11.1, server-side web fetches did not reapply WEBFETCHFILTERLIST or private-address controls to HTTP redirect destinations when AIOHTTPCLIENTALLOWREDIRECTS was enabled. An authenticated user...

CVE-2026-87017

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.7.0 until 0.11.1, the built-in knowledge search tool passed the caller's readable knowledge identifiers through a metadata filter, but the search methods in eleven shipped vector backends ignored that...