Open Webui vulnerabilities
173 vulnerabilities
Known vulnerabilities in Open Webui products, newest first, with CVSS severity, EPSS, KEV listings and ransomware use, across 2 products.
Products
2- Open Webui165 vulnerabilities
- Open Webui/Open Webui8 vulnerabilities
CVE-2026-109300open-webuiopen-webui
EPSS score0.18%
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.CVE-2026-109290open-webuiopen-webuiEPSS score0.26%
Open WebUI from 0.11.1 before 0.11.4 contains a stored cross-site scripting vulnerability in DocxPreview.svelte that allows authenticated users to execute script by uploading crafted DOCX attachments. Attackers can embed an OOXML altChunk HTML part or script-scheme hyperlink to steal a previewing administrator's session token from local storage and take over the instance.CVE-2026-109295open-webuiopen-webuiEPSS score0.31%
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.CVE-2026-109285open-webuiopen-webuiEPSS score0.20%
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.CVE-2026-109294open-webuiopen-webuiEPSS score0.31%
Open WebUI from 0.6.42 before 0.11.4 contains an uncontrolled resource consumption vulnerability that allows authenticated users to exhaust server memory by supplying compressed remote image URLs in chat messages. Attackers can point the image field at a host returning gzip-encoded responses, which get_image_base64_from_url decompresses unbounded, causing denial of service for all users.CVE-2026-109283open-webuiopen-webuiEPSS score0.21%
Open WebUI from 0.11.1 before 0.11.4 contains an authorization bypass in the OAuth token exchange endpoint, which reads role claims only from the provider's userinfo response and keeps the user's existing role when no roles claim is found, ignoring roles sent only in the ID token. Users with a linked account whose identity provider role no longer satisfies the OAuth role policy can send a valid provider access token to POST /api/v1/auths/oauth/{provider}/token/exchange to obtain a session retaining their previous role.CVE-2026-109291open-webuiopen-webuiEPSS score0.28%
Open WebUI from 0.6.33 before 0.11.4 contains a cross-site scripting vulnerability that allows authenticated users to execute script in victims' sessions by storing javascript: URLs in citation embed_url fields. Attackers can share a crafted chat whose citation, when clicked, is passed to window.open, letting them steal localStorage.token and act as the victim.CVE-2026-109293open-webuiopen-webuiEPSS score0.29%
Open WebUI from 0.11.0 before 0.11.4 contains an information disclosure vulnerability that allows authenticated non-admin users with tool export permission to obtain tool source code shared with them read-only. Attackers can request GET /api/v1/tools/export to retrieve the full Python source of read-only shared tools, exposing embedded API keys and credentials.CVE-2026-109286open-webuiopen-webuiEPSS score0.14%
Open WebUI from 0.7.0 before 0.11.4 contains a cross-origin message handling vulnerability in SyncStatsModal that allows any website to steal a signed-in user's session token by posting unvalidated verify:chat messages. Attackers can supply a path-traversal chat id redirecting the authenticated stats export request to the auths endpoint, receiving the victim's JWT for full API access.CVE-2026-109298open-webuiopen-webuiEPSS score0.39%
Open WebUI 0.11.0 before 0.11.4 compiles user-chosen grep patterns for its knowledge and chat file search tools with a regex engine that expands nested counted repetition unbounded at compile time and caches the result. Authenticated users can have the model call grep_knowledge_files with short nested-repetition patterns, blocking the event loop and exhausting worker memory.CVE-2026-109284open-webuiopen-webuiEPSS score0.21%
Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access. Shared folder members downgraded to read-only can call POST /api/v1/chats/{id}/fork on chats they created there while they had write access, inserting attacker-controlled chats visible to the folder owner and members.CVE-2026-109296open-webuiopen-webuiEPSS score0.27%
Open WebUI before 0.11.4 contains a missing authorization vulnerability that allows authenticated users to reach disabled model provider backends by supplying an explicit backend index. Attackers can pass the index as a path segment or query parameter on Ollama and OpenAI-compatible listing routes to trigger requests carrying configured API keys, read version strings, and enumerate connections.CVE-2026-109289open-webuiopen-webuiEPSS score0.21%
Open WebUI from 0.8.8 before 0.11.4 contains an improper authorization vulnerability that allows deactivated users to keep executing terminal commands through an already open terminal WebSocket. Because the terminal proxy route in terminals.py checks access only on the first message, deactivated users can keep running commands and reading or writing files on the terminal server.CVE-2026-109288open-webuiopen-webuiEPSS score0.23%
Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim's JWT from local storage, including admins' tokens.CVE-2026-109292open-webuiopen-webuiEPSS score0.32%
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.CVE-2026-109299open-webuiopen-webuiEPSS score0.38%
Open WebUI from 0.9.0 before 0.11.4 contains a denial of service vulnerability that allows authenticated users with automations permission to stall the instance by submitting unsatisfiable recurrence rules. Attackers can repeatedly send rules like February 30th to the automations create or update endpoints, blocking the shared event loop for seconds per request.CVE-2026-109287open-webuiopen-webuiEPSS score0.22%
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.CVE-2026-109297open-webuiopen-webuiEPSS score0.31%
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.CVE-2026-109572open-webuiopen-webuiEPSS score0.30%
Open WebUI from 0.8.6 before 0.11.4 contains a privilege escalation vulnerability in the terminal proxy that allows authenticated users to reach the Terminals administrator API with the shared key attached. Attackers can send requests through /api/v1/terminals/{server_id}/{path} to list or stop other users' terminals and modify terminal policies, injecting environment variables into other users' terminals.CVE-2025-65959Npmopen-webui+2EPSS score0.24%
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.6.37, a Stored XSS vulnerability was discovered in Open-WebUI's Notes PDF download functionality. An attacker can import a Markdown file containing malicious SVG tags into Notes, allowing them to execute arbitrary JavaScript code and steal session tokens when a victim downloads the note as PDF. This vulnerability can be exploited by any authenticated user, and unauthenticated external attackers can steal session tokens from users (both admin and regular users) by sharing specially crafted markdown files. This vulnerability is fixed in 0.6.37.