Jeudi 15 octobre 2026

open-webui

Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled.

open-webui

Open WebUI 0.11.0 before 0.11.4 contains a denial of service vulnerability in the automation recurrence-rule validator, whose sub-daily frequency guard parses rule text more strictly than the calendar library that executes it. Users permitted to create automations can submit whitespace-folded rules (or, in 0.11.0, lowercase frequencies or omitted RRULE prefixes) that expand per-second synchronously, blocking the shared event loop for minutes per request and on every scheduler poll.

open-webui

Open WebUI from 0.11.0 before 0.11.4 contains a regular expression denial of service vulnerability that allows authenticated users to stall server workers via file search patterns. Attackers can instruct the model to call grep_knowledge_files or grep_chat_files with a catastrophically backtracking regex, blocking the event loop for two seconds per repeated call.

open-webui

Open WebUI from 0.6.27 before 0.11.4 contains an information disclosure vulnerability that allows destination servers to obtain user session cookies by receiving the full browser cookie jar on OAuth-mode connections. Operators of OpenAI-compatible connections, OpenAPI tool servers or terminal servers can capture forwarded session cookies from routine requests and replay them to hijack accounts, including administrators.

open-webui

Open WebUI from 0.9.6 before 0.11.4 contains an authorization flaw where the knowledge base file listing does not verify that a supplied directory_id belongs to the requested knowledge base. Users with read access to any knowledge base can supply a retained foreign directory UUID to GET /api/v1/knowledge/{id}/files. The returned breadcrumbs expose folder names, owner user ids and knowledge base ids of that directory and all its ancestors.

open-webui

Open WebUI from 0.6.0 before 0.11.4 contains an improper access control vulnerability in has_access_to_file that lets former knowledge base collaborators keep file access via stale cached knowledge base references. Attackers with read or write grants can download removed files through the file content endpoint or delete them, including from the owner's private knowledge bases.