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Medium · 6.5 CVE-2026-88000 EUVD-2026-75185GHSA-3cgp-3cqx-j8w2PYSEC-2026-3877

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

Published Sep 9, 2026 · Updated Sep 10, 2026 · Assigned by GitHub_M

Description

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/{message_id} used the chat-history deletion helper in backend/open_webui/models/chats.py to follow childrenIds without recording visited message identifiers. An authenticated user could store a cyclic chat tree and delete a message, causing a synchronous infinite loop on the server request loop that blocked every user's requests until the process was killed. This issue is fixed in version 0.11.1.

Affected products

VendorProductAffectedFixed
open-webui open-webui >= 0.10.0, < 0.11.1 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI open-webui >= 0.10.0, < 0.11.1 0.11.1 GHSA-3cgp-3cqx-j8w2

References